an independent steam-valve for the high-pressure cylinder, shown at a, is added, so as to avoid damaging the action of the low-pressure valve and the high-pressure exhaust.

As an example of this practice, in an engine of 275 horse-power of this type, now being constructed for a United States steamtender, a piston-valve is used for the steam-valve of the highpressure cylinder, and a slide-valve for admitting the steam into the low-pressure cylinder and exhausting it therefrom. small engines an ordinary governor, not shown in the cuts, is usually attached.

For

The special advantages claimed for this engine are compactness, a low centre of gravity, and particularly the fact that all the moving parts are in pairs, equal, and acting in opposite directions, thus securing a perfect mechanical balance, and adapting the engine to high rates of speed without sensible vibration.

As evidence of the adaptability of this engine for electric-lighting purposes, it may be stated that it has been attached to a thousand-light dynamo, which it ran at the rate of seven hundred and fifty revolutions per minute; and so steady was its performance, and so well was it governed, that, when the entire load was thrown off by means of a switch, it made no perceptible change in its running. The throwing on and off of such a load is a very severe test for an engine.

The following extract is taken from the report of a board of government engineers who had examined this engine with a view to determining its adaptability for the various uses of the government: "The engines are compact, and the working parts are reduced to a minimum; and they have the advantage of long connecting rods, and a reduction of height over the ordinary vertical engine with the same length of connecting rod. They are also well-balanced engines."

THE WITHDRAWAL OF ALCOHOL FROM BOND FOR SCIENTIFIC PURPOSES, FREE OF TAX.'

IT may not be generally known to the members of this associa tion that they can obtain their supplies of alcohol for use in their chemical laboratories free of the internal revenue tax of ninety cents per proof gallon, or $1.70 per gallon of ninety-five per cent alcohol, by complying with certain regulations prescribed by the secretary of the treasury, in accordance with section 3297 of the Revised Statutes of the United States.

The Law.

This section provides that "the secretary of the treasury is authorized to grant permits to any incorporated or chartered scientific institution or college of learning to withdraw alcohol in specified quantities from bond without payment of the internal revenue tax on the same, or on the spirits from which the alcohol has been distilled, for the sole purpose of preserving specimens of anatomy, physiology, or natural history belonging to such institution, or for use in its chemical laboratory; provided, that applications for permits shall be made by the president or curator of such institution, who shall file a bond for double the amount of the tax on the alcohol to be withdrawn, with two good and sufficient sureties, to be approved by the commissioner of internal revenue, and conditioned that the whole quantity of alcohol so withdrawn from bond shall be used for the purposes above specified, and for no other, and that the said president or curator shall comply with such other requirements and regulations as the secretary of the treasury may prescribe. And if any alcohol so obtained is used by any officer, as aforesaid, of such institution, for any purposes other than those above specified, then the said officer or sureties shall pay the tax on the whole amount of alcohol withdrawn from bond, together with a like amount as a penalty in addition thereto."

The above provisions are further extended by the act, approved May 3, 1878 (20 U. S. Stat. 48), which provides :

"That the secretary of the treasury is authorized to grant permits, as provided for in section thirty-two hundred and ninetyseven of the Revised Statutes of the United States passed at the 1 Paper read before the Association of Official Agricultural Chemists at Washington, D C., Sept 11, 1889.

first session of the Forty-third Congress, to any scientific univer. sity, or college of learning created or constituted such by any State or Territory under its laws, though not incorporated or chartered, upon the same terms and subject to the same restrictions and penalties, already provided by said section thirty-two hundred and ninety-seven provided further, that the bond required thereby may be executed by any officer of such university or college, or by any other person for it, and on its behalf, with two good and sufficient sureties, upon like conditions, and to be approved as by said section is provided."

Documentary Evidence required from a Scientific Institution before it can enjoy this Privilege.

To obtain this privilege for its chemical laboratory, an incorporated or chartered, or not incorporated or not chartered, scientific institution, university, or college of learning must, at the time of its original application, clearly show, by a copy of its charter, arti cles of incorporation, or other documentary evidence, that it is an institution duly entitled to such permit by possessing a suitably equipped chemical laboratory and otherwise.

stored in said warehouse on the day of, 18—, described as follows: viz, number of packages; marks and serial numbers of packages; numbers of warehouse-stamps; wine-gallons; degree of proof; proof-gallons; taxable gallons; and amount of tax; for the sole purpose of use in the chemical laboratory of the institution, located at -, in the State of of which institution" the signer is one of the persons above mentioned. The application in all cases must be sworn to, or affirmed, before an officer authorized to administer oaths."

Character of the Bond.

The bond, required to be filed with the first application, must be in a penal sum of "not less than $200, and never less than double the amount of tax on the alcohol withdrawn at any one time," is signed by the applicant "as principal, and with two or more sureties, who shall not be officers of the institution in which the alcohol is to be used, but shall be residents of the United States judicial district in which such institution is located." In the case of "an incorporated institution, its name should be signed to the bond as principal, and its corporate seal affixed by its duly authorized officer, who should also sign his own name as such officer."

The bond is conditioned that "the entire quantity of alcohol" intended to be withdrawn "from distillery warehouse, without payment of tax," by the said principal, will be “for the sole purpose of use in the chemical laboratory of the" said institution, "in the city or town of, of the county or parish of and State of

and for no other purpose."

The bond is known as a "continuing bond; i.e.," withdrawals may be made from time to time," "by the said principal," "until this bond shall have been revoked or cancelled by direction of the secretary of the treasury," of certain alcohol for use "by the said institution, or the proper officer thereof, for the purpose above specified, and for no other purpose." The principal of said insti tution shall, as to each lot of alcohol so withdrawn, produce within" the time "fixed by the collector accepting the hond," "from the date of such withdrawal," "proof satisfactory to" the collector of internal revenue of that district," and to the commissioner of internal revenue, that the said alcohol has been so used for the purpose above specified, and for no other purpose." He shall also comply with such other requirements and regulations as the secretary of the treasury may prescribe;" and according to the last paragraph of section 3297, Revised Statutes, "the said officer or sureties are bound by this bond to pay to the collector "the tax on the whole amount of alcohol withdrawn from bond, together with a like amount as a penalty in addition thereto," "in case said

alcohol, or any part thereof, shall be used for any purpose other than that specified."

Bond and Application to be filed with the Collector for Approval.

The "bond, together with the first application for permit, will be deposited by the applicant with the collector of internal revenue for the district where the institution in which the alcohol is to be used is located." It is the collector's duty to forward the bond and application to the commissioner of internal revenue, with his certificate of approval, etc. He keeps "a copy of the bond, or a memorandum of its date, penal sum, and the names of the signers; and whenever an application for alcohol is made after the first one, the collector will certify to the commissioner of internal revenue that the bond remains good, or will notify him of any change affecting the responsibility of the signers." "Upon the approval of the bond by the commissioner of internal revenue," applications may be made on the prescribed form "for the withdrawal of alcohol as occasion may require" by the duly authorized officer or agent: "provided, the penal sum of the bond is equal to double the amount of tax on the alcohol to be withdrawn, after deducting all outstanding charges on the bond." The commissioner transmits the applications "to the secretary of the treasury, with a notification of the approval of the bond when the first application is forwarded, and afterwards with a reference to the bond under which the application is made."

Cancellation of Bond.

To cancel the bond" or for the purpose of obtaining a credit on said bond," a sworn certificate is “required of the officer or officers of the institution under whose direction or supervision the alcohol has been used." The certificate is "filed with the collector named in the bond, and if approved, to be forwarded by him to the commissioner of internal revenue with his approval indorsed thereon." Extension of Time named in Bond.

It sometimes happens that the alcohol is not entirely used up in the time specified in the bond, and that consequently "the principal to the bond is unable, for good cause, to furnish the required proof" of such use. He may obtain an extension of the time named in the bond upon application to the commissioner of internal revenue, "accompanied by the consent of the sureties to the bond to such extension; such application and consent to be approved by the collector with whom the bond was originally filed." "The extension asked for must be for a specified time," "not exceeding one-half the period named in the bond." The application "must be sworn to," and state "the reasons why the conditions of the bond as to the presentation of proof have not been complied with." The consent of the sureties must be "under seal, and witnessed as in the case of giving an original bond."

Permits to be issued by the Secretary of the Treasury. "The secretary of the treasury will issue," "upon receipt of the application" "and notice of the approval of the bond," "and transmit through the commissioner of internal revenue, a permit in duplicate, one copy of which will be forwarded to the applicant and the other copy to the collector of internal revenue for the district in which the distillery warehouse is located," to withdraw from the specified warehouse the number of proof gallons of alcohol described in said application.

The collector notifies "the storekeeper at the bonded warehouse from which the spirits are to be withdrawn" of the receipt of the permit, a copy of which is sent to him, and authorizes him "to deliver the spirits to the person named therein, or his duly-authorized agent, without the payment of tax, upon delivery to such storekeeper and cancellation by him of the duplicate permit issued to such person." This "cancellation shall be made by writing across the face of said duplicate permit the words 'The spirits herein described were delivered to the person herein named this -day of —, 18—;' to be signed by the storekeeper." "There shall also be indorsed on the back of said permit the following receipt: Received the spirits within mentioned this day of

18-,' which receipt shall be signed by the person named in said permit."

Such in detail are the steps to be followed as prescribed by the regulations of the secretary of the treasury under date of March 26, 1889.

Blank forms are not furnished by the Treasury Department; and such forms, either printed or written, must be supplied by the parties making the application and bond. The forms to be followed are contained in Circular No. 34, 1889, of March 26, 1889, Treasury Department.

Are Agricultural Experiment Stations entitled to this
Privilege ?

The laws, quoted above, restrict this privilege of the withdrawal of alcohol free of tax to four specified beneficiaries: viz., (1) “ any scientific institution" or (2) "college of learning," "incorporated or chartered;" (3) "any scientific university " or (4) " college of learning I created and constituted such by any State or Territory under its laws, though not incorporated or chartered;" which are further qualified as using alcohol (a) to preserve specimens of anatomy, (b) physiology, or (c) natural history, or (d) to be employed in its chemical laboratory. With the latter qualification the members of this association are chiefly concerned.

The act, approved March 2, 1887, "to establish agricultural experiment stations in connection with the colleges established in the several States under the provisions of an act approved July 2, 1862, and of the acts supplementary thereto " (24 U. S. Stat. 440), commonly called the "Hatch bill," provides in section 8 that these agricultural experiment stations established by law" may or may not be "in connection with any university, college, or institution not distinctly an agricultural college or school," or may or may not be "separate from" "colleges entitled" "to the benefits of this i.e., land-grant agricultural colleges.

act;

...

Section 2 provides "that it shal! be the object and duty of said experiment stations to conduct original researches or verify experiments on . . . the chemical composition of useful plants at their different stages of growth; . . . the analysis of soils and water; the chemical composition of manures, natural or artificial; with experiments designated to test their comparative effects on crops of different kinds; . . . the value of grasses and forage plants; the composition and digestibility of the different kinds of food for domestic animals; the scientific . . . questions involved in the production of butter and cheese; and such other researches or experiments bearing directly on the agricultural industry of the United States as may in each case be deemed advisable, having due regard to the varying conditions and needs of the respective States or Territories."

These experiments evidently require a well-equipped chemical laboratory, in which alcohol would be often used as a solvent and re-agent in addition to any use of it as a fuel in the laboratory.

Taking the above quoted qualifications and provisions of law into consideration, it would seem that any agricultural experiment station that is established in conformity to the provisions of the act of March 2, 1887, by any State or Territory as such, when such station is connected with a "university or college of learning," is entitled on presentation, by its duly authorized officer or agent, of documentary evidence to that effect submitted to the secretary of the treasury through the commissioner of internal revenue and the collector of internal revenue of the district in which the experiment station is situated, and by filing a bond and otherwise conforming to the regulations, above specified, to the privilege of withdrawing alcohol, free of tax, for use in its chemical laboratory; also that when the experiment is not connected with a college, etc., it may obtain free alcohol under the same regulations, provided it is shown to the satisfaction of the internal revenue officers and the secretary of the treasury that it is of itself a "scientific institution" as construed by those officers, that is, such an institution whose object is educational. EDGAR RICHARDS.

WHEN an electric current, says a French contemporary, is led through the leaf of a rose, the leaf loses its color, leaving a white line. This peculiarity was recently turned to account at a great dinner in Paris, when, instead of the ordinary card, the seat of each guest was indicated by his name being inscribed in white letters upon a rose-leaf in his couvert.

ELECTRICAL NEWS.

THE TELEGRAPHONE. A problem heretofore only partially and unsatisfactorily solved is the registration of telephonic messages so that they can be received at pleasure. Most of the efforts in the direction of its solution have been towards using the induced currents from the Blake transmitter in producing a record on the phonograph at the other end of the line. An amplifying trumpet has been used, and the vibrations of the diaphragm of the receiving instrument have been recorded on the cylinder of the phonograph. It has thus far been necessary that an operator should be at both ends of the line, and any slight electrical disturbances that would interfere with the delicate induced currents naturally have blurred the phonographic record. An instrument has lately been patented and brought out that will no doubt be of actual use and commercial value. It is called the "telegraphone," and is the invention of Mr. Malone Wheless of Washington, Ď.C. Mr. Wheless does not depend upon the transmitter currents for his impressions: the speaker's voice is registered on the cylinder mechanically, the record being of the nature of dots and dashes on a strip of paper. A stylus connected with a light primary battery moves along these impressions, producing current interruptions of a make-and-break character, almost similar to the Morse code, and reproducing the impressions on the registering cylinder at the other end of the line. In practice, if A desires to send a telephonic message to B, who is not at home, he calls him up in the usual way. Receiving no answer, he turns a switch which throws in the battery power and sets the cylinder at the other end in operation. He then talks into his transmitter. The vibrations are transferred to the cylinder, and the stylus sets up a series of waves, reproducing the impressions at the other end, and registering the message. A then reverses his switch, and the message is repeated back to him. Should any part of the message be inaudible, he simply fills in the blurred words or sentences, and the record at the other end is then satisfactory and complete. Upon B's arrival home, he finds the message waiting for him, corrections and all; and if its importance demands it, he can have it repeated to himself as many times as he chooses. The inventor claims that the apparatus can be manufactured and sold outright at a very low figure, and it is difficult to foretell whether its usefulness or novelty will be the most interesting feature.

ELECTRICAL EXECUTIONS. This subject will enjoy popular interest as long as the law now supposed to be in force remains upon the statute books of the State of New York. It seems to have been adopted for the reason that those having the matter in hand knew less about death from electricity than from any other cause, and also because the expert advice at hand seems to have been discolored with the tainted aniline of business jealousy. The subject, from a scientific standpoint, is of itself sufficiently interesting and baffling; but when the people realize, as they now must, that the enactment of the law was due largely to the influence of a party whose object was not so much to furnish a quick and painless death as to enrich himself, it causes a cold shiver of horror to pass over the community. Exactly how many volts of electrical pressure will kill is as uncertain as would be the number and force of the strokes from a club that would produce death. A number of persons, among whom may be mentioned Mr. T. Carpenter Smith, the well-known electrical engineer, have been accidentally subjected to the action of the very type of machine intended to be used by the authorities, and have lived. Other persons have died instantly from a much lighter shock. Only a few days ago expert Henry of this city was instantly killed by 1,000 volts. Since that time a Buffalo lineman lived in agony for forty minutes after suffering the enormous pressure of 2,000 volts. Will electricity kill? Certainly it will kill, but exactly how applied, and how many volts?

ENCROACHMENT OF ELECTRICITY UPON GAS IN HOUSELIGHTING. Gas, which is now almost universally employed, has not come into use in a moment. The difficulties attending its distribution at great distances from the source of supply have never called for more than mechanical skill and ingenuity. But with electrical distribution the problem to be solved is not how to cover a certain territory with the mains and feeders of an electric-light system, but how to do it with a fair profit on the investment.

Among the methods making rapid strides is that of the distribution of electricity by means of the alternating current. The very type of machine which the authorities consider so dangerous to life will no doubt be that which will eventually solve the problem of universal electric house-lighting. The current in the outside mains is of a high pressure, — 1,000 volts or more, as the case may be. This current is transformed by means of the converter to a lower potential, and carried into houses at the safe and low pressure of only 50 or 100 volts. More and more private residences are being wired for and lighted by electricity every day, and this is the case more especially in small and growing towns than it is in large cities. Little towns like Marshall, Tex., Vicksburg, Miss., and the small towns of the Far West, are falling into line, and availing themselves of every fresh improvement that will increase the returns from investment and enhance the worth and reliability of the light itself. In the New England States this condition of things to-day obtains to such an extent that nearly every week finds some gas company absorbing the local electric-light company out of pure self-defence, and continuing the work.

AMERICAN ELECTRICAL ENTERPRISE IN LONDON. — The increased and increasing investment of English capital in American institutions has caused much comment. American capital is not doing precisely the same thing in England, but the establishment of a Westinghouse Electric Manufacturing Company in London is a fact that must excite comment and admiration as well. The Westinghouse Electric Company of London has been organized with a capital of $3,000,000. The factory is to be located on York Road, adjoining the Westinghouse Air Brake Works. Other electric companies are extending themselves abroad, but this is one of the most striking and recent examples of such extension.

ELECTRIC TANNING. It is now claimed that an electrical process for tanning hides has been devised which reduces the time of the operation from six months or a year to twenty-four hours, turning out leather of equal quality. The cost is said to be reduced more than one-half. It is usually the case with quick processes that the material so turned out is in many respects inferior to that manufactured in the usual way by skilled workmen who have taken advantage of the experience of others, and perfected their process after years of work and study. The new system alluded to does not partake in any way of the nature of an "electric sugar" concern, as each step has been made public and carefully described. When it is proved that the leather thus turned out is equal in all respects to that now manufactured, the process will possess more interest than its shadowy entity now elicits.

ELECTRIC SIGNALLING FROM SHIPS. If there is any thing in our naval service that is inefficient and undeveloped, it is the system known as "wigwag" signalling. A flag with a short staff is waved to the right and left a given number of times for each letter of the alphabet according to the code, and the speed attained is remarkable for its slowness. Lack of speed can also be attributed to insufficient practice of those using the code, although the exercises enforced on board most vessels have given rise to a number of bright, quick signalmen among the apprentice boys who do the service proud in this respect. But with the most expert signalmen the speed attained is so unsatisfactory that a quicker method will no doubt before long come into use. Where vessels are fitted up with electric lights, a system of signals is sometimes employed, extending the use of the "wigwag" code to two incandescent lamps suspended somewhere in the rigging for night work. In such cases a double key is used, the illumination of one lamp being read "one," and of both lamps at the same instant, "two;" the letters of the alphabet being represented by combinations of "one and two." Although these flashes can be made much faster than the motions of the flag in daylight, still it is so easy to exceed the possible speed of the reader on the other vessel or on shore, that little increase of efficiency is attained. It takes but two or three months to become tolerably proficient in the use of the ordinary key and sounder, reading from fifteen to twenty words per minute at least. The same device that now flashes out the clumsy naval code could be employed in connection with the Morse alphabet with a great saving of time. Practice in taking from a telegraph instru ment makes the ear or eye practically drink in the words spelled

out, without a conscious analysis of individual letters. Messages can be flashed from the rigging of ships with almost the rapidity of telegraph messages over ordinary wires. Take, for example, the message “The uniform of the day will be clean blue." This sentence of only nine words, if sent at the rate of nine words per minute according to the regular navy code, could be read by about one officer out of ten. Few officers can read that fast. The average speed of signalling, then, by the "wigwag" system is probably less than nine words per minute. It ought to be more. Mr. Edison has suggested an adaptation of his train telegraph system to the use of ships at sea. If a sufficient area of insulated metallic surface could be exposed somewhere, either on deck or aloft, it might be possible to telegraph from ship to ship by electrical induction without the use of connecting wires, just as Edison in a moving train takes messages from the wires along the track. We know of no experiments in this direction as yet, but the field is certainly an interesting and promising one.

AN ELECTRIC LOCOMOTIVE. - Will trains eventually be run by electricity? The electrician is met by this question almost daily, and his only reply is that they will if the problem of their commercial success be finally solved. Of course, running machinery of any kind from primary batteries is commercially out of the question. Every one with even the most rudimentary knowledge of the science realizes that it takes a certain consumption of zinc or other metal to liberate a certain amount of energy, and that this method is altogether too expensive to be practicable. However, there is now being constructed at the locomotive works, Rome, N.Y., an electric locomotive which is the first engine, we believe, attempted to be run on regular railroad-tracks from storage-batteries. The ordinary rotary type of electric motor will not be employed. Suction-magnets are to be located on either side of the piston, and the current supplied from storage-batteries in the firebox. The locomotive is smaller than the usual type, and has driving-wheels of less diameter. In a few days the trial trip will be made, and Science will give its readers the result. The question will be asked, "How is it possible to utilize the energy of storagebatteries at such a great loss from the original energy of coal, and still be as economical as the steam locomotive?" That is the fact that remains to be proved. It should be remembered, however, that it may be possible to generate electricity by means of large economical compound condensing engines with a final loss at the motor not much greater than that which is found in that great wasteful gormandizer of coal, the steam locomotive.

NOTES AND NEWS.

THE Rev. Mr. Frizelle of Bushmills, England, narrates, in Science Gossip, that he witnessed a trial of a rook by his comrades for the act of stealing sticks from other nests. The other rooks assembled round the culprit, and cawed for a considerable time, when the unfortunate bird was condemned to suffer the penalty, and he was then and there set upon and pecked to death. Two magpies were present, who appeared seemingly as witnesses.

- The University of Jena is going to hold autumn courses for teachers in the various sciences. The course, commencing Sept. 23, is to last a fortnight, and comprises the following subjects: psychological principles of education, instruction in chemical experiments, the same in physical science, botanical observations and morpho-physiological experiments, animal biology, school hygiene, physical geography, and colonization.

- Any one who takes a walk abroad in the rural parts of France, when farming operations are going on, says J. W. Slater in Science Gossip, will often see small children following the plough armed with small pitchers, into which they put all the white, fat grubs of the cockchafer which are turned up. In England the rooks do this work, without young children being withdrawn from school or from play. But the French sportsman has nearly extirpated these useful birds. A recent iniquity, according to a contemporary, is the systematic destruction of the swallows on their return from Africa. Emissaries of the Paris modistes fix up on the shore, about the points where the birds usually land, long wires connected with

powerful electric machines. The wearied swallows perch on the wires, and are struck dead by scores. Their bodies are then sent off to Paris to ornament women who are a disgrace to humanity. The saddest feature is that our contingent of martins and swallows arrive by way of France, and will doubtless be cruelly decimated.

- Professor Beal finds that the peculiar markings in bird's-eye maple do not occur in young trees up to about three inches in diameter, nor very high up in trees which are very much pitted at the base. A specimen taken fifty feet above the ground, Garden and Forest states, showed no trace of bird's-eye, while another from near the base of the same tree was very strongly marked. If the cause of these formations could be discovered and used to produce the marks, it would add greatly to the market value of the timber, for the wood of this maple and of other trees somewhat similarly marked is comparatively scarce and in great demand for

veneers.

– F. W. Galton, the famous writer on the subject of inherited qualities, proposed to the Congress of Psychological Physiology to issue in the form of a document a series of questions intended to draw from scientific observers the world over the results of their experience touching the inheritance of acquired habits, mental, scientific, or social. He laid before the congress a first-rate conundrum. He told of an aquarium divided into two parts by a plate of glass perfectly transparent, and therefore invisible to the fish. In one division there was a pike, in the other a gudgeon. Every time the pike saw the gudgeon, he rushed to seize him, but every time he was stopped by the plate of glass. He did not learn soon, but for several months made this rush, and bruised his nose against the glass. Finally he came to understand that for some reason inscrutable to his intelligence he could not seize the gudgeon, and then he gave it up. He now swam about, seeing the gudgeon constantly, but paying no attention to it. Then the plate of glass was removed. This made no difference, the pike did not attempt to take the gudgeon. He had acquired the habit of leaving the gudgeon alone. The conundrum was, would his descendants inherit that habit, or possess the original impulse of their kind? Illustrations of this kind, or showing the operation of the principle of acquired inheritance, are what Mr. Galton wants.

- The great chart of France, showing the geological formations of the country on a scale of 1:500,000, has at length been completed, and a copy deposited with the Academy of Sciences at Paris. It is over fifty years since MM. Dufrenoy and Elie de Beaumont published a geological map of France on the same scale, and since that period the rocks of the different provinces have been more intimately studied. In 1882 the new general map was begun under the superintendence of the Commandant Prudent, and published by the depot of fortifications. It has just been finished, and, according to the Scottish Geographical Magazine, is an example of the most accurate cartography. Local geologists have contributed to the work as well as the government surveyors, and the scale of 1:500,000 has been adopted in deference to the wish expressed at the geological congress of Bologna in 1881, so that different countries can more easily compare the map with their own. The scale of colors recommended at that congress has also been followed,- that is to say, the sedimentary series is represented by the colors of the spectrum in their regular order. Thus the trias is colored violet, the Jurassic blue, the cretaceous green, and the tertiary yellow. Each of these general colors is subdivided into shades, which are deeper according as the rocks are more ancient. This is the first time the method has been employed on a large work, and it has given every satisfaction, since it allows the systems of rocks and their different gradations to be readily recognized. The eruptive rocks have been colored in different shades of red, and the crystalline schists in carmine. As for the primary rocks, on which the congress came to no decision, the authors of the map have been guided by the same principles in choosing their tints. The Silurian has therefore been colored a flesh pink, and the Devonian a red brown. The carboniferous, according to old habit, has been colored black and deep gray, while the Permian is represented by a yellowish gray. No fewer than fifty shades are employed; but all are easy to distinguish.