sitions have been sent to us of late years with a request that we assist the proposers in presenting their claims to the French government. In almost every instance the proposers have shown an absolute lack of experience, both as to the insect and as to the methods they recommend.

In

The question of the winter egg, so called, has again occupied much of the attention of the commission, which places great confidence in the researches in regard to it of one of its eminent members, Balbiani, who has been instructed to continue his investigations. reference to this egg, and the importance of destroying it, there has, of late, been much discussion in France; and we may repeat our answer to the following question, recently put to us by one of the first French investigators into the life-history of Phylloxera :

"L'oeuf soi-disant d'hiver de M. Balbiani est-il indispensable à la reproduction du Phylloxera, ou bien la reproduction agame vous parait-elle possible durant plusieurs années ou même indéfiniment?”

Our reply was, that the impregnated egg (we prefer this term to winter egg) is indispensable to the continued reproduction of Phylloxera, and that normally it is produced annually in the cycle of the insect's life; but that agamic multiplication may, under favoring conditions. extend to the third or fourth year, and, for aught we know, longer.

In reading over Targioni-Tozzetti's criticism of Balbiani, and the latter's reply, in late numbers of the Comptes rendus de l'académie, we felt, that, so far as our own observations and experiments have gone, both were in a degree right, and both wrong. There is no question but that Balbiani is essentially right in his conclusion as to the necessity for the impregnated egg at some period during the annual development, under the conditions of our changing seasons. All the facts ascertained, as well as all analogy from what is known of the lifehistory of other species of the family, point to the accuracy of that conclusion.

Yet ex

periments enough are on record to show, that, where the conditions of early spring and summer are artificially maintained, agamic reproduction in aphides may be greatly extended, and even go on to the third or fourth year.

Of course, this possibility of such continued. agamic multiplication does not change the practical fact of what does take place in an ordinary year under ordinary seasonal changes. Balbiani, therefore, is theoretically quite right in insisting on the importance of the destruction of his winter egg. Just here, however, is

where we shall have to differ from him as to the practical value of attempts to do so, and for the following reasons:

It is a universally conceded fact, that the species hibernates chiefly in the dormant larval state underground. Now, even supposing that every so-called winter egg could be destroyed, we know positively that the vines would still be infested, and that new impregnated eggs would again occur the ensuing fall or winter. Therefore, even on Balbiani's belief, these eggs would have to be annihilated for at least two consecutive years to do any good. But, unfortunately, all methods of annihilation heretofore proposed have proved impracticable, and, in fact, impossible.1 Decortication must always be but partially successful, as the eggs are not confined to the loose bark or to the older portions of the vines. Moreover, our researches in this country (and it seems to us that experience in Europe corroborates them) show conclusively that this impregnated egg is not necessarily a winter egg, for it is extremely rare, and difficult to discover, during winter, or at any time: hence, and for the reason that larval hibernation prevails, we are justified in one or the other of the following conclusions::

1°. That the sexual females do not necessarily confine the impregnated egg to the stems and branches, but lay them also at the base of the vine, or even beneath the ground; 2°. That hypogean, apterous females also produce the sexed individuals underground; 3°. That the impregnated egg hatches the same season that it is laid.

Now, there are certain facts of experience that would give some warrant to all three of these conclusions, the first and second being fully justified by facts recorded by Balbiani and ourselves. The third statement we have proved true with Phylloxera Rileyi; and M. P. Graels has also proved it for P. vastatrix in Spain (see Amer. nat., 1881, p. 483).

Thus we have little faith in the results of decortication; and we have already expressed much the same views in the American naturalist, in our eighth Missouri report, and in our report to the Department of agriculture for 1878, p. 83.

With regard to the use of American vines as stocks on which to graft the more susceptible French vines, the commission admits the success of the former in rich or deep soils, but concludes that they leave something yet to be

1 The eggs, in the rare cases where they are found, are con cealed as much as possible in minute cracks and crevices, so that mechanical decortication cannot well reach them all; while the application of heat, as by torches, would not destroy them all unless intense enough to injure the vines.

desired on light or superficial soils. It seems to us that this amounts to little more than saying that a vigorous vine cannot be grown on a poor soil; the fact being that the American vines for this particular purpose have made their way against much opposition, and remain to-day the best solution, all things considered, of the Phylloxera question.

The commission finally concluded that the prize of 300,000 francs be still reserved, but maintained. It seems to us that some disposition should be made of this prize, as the commission must not expect to get any more satisfactory means of dealing with the pest than those already proposed, that are based on experience and sound scientific principles. By this we mean that the treatment of any such underground pest that has so varied a life-history must necessarily involve a given amount of time, money, and labor, regardless of the particular substance or means employed; and to look for a remedy' that shall involve neither is to look for the impossible, - the miraculous. Those who were the first to suggest and prove the value of resistant American vines, those who established the value of submersion and bisulphide of carbon, and those who have helped toward a sound knowledge of the insect's life-history, all deserve recognition.

The methods recommended by the commission for the year 1883, aside from the use of the American vines, are the old ones of submersion, bisulphide of carbon, and sulphocarbonate of potassium. C. V. RILEY.

CALIFORNIA AGRICULTURE. University of California. College of agriculture. Report of the professor in charge to the president, being a part of the report of the regents of the university. 1882. Sacramento, State, 1883. 179 p. 8°.

THIS report includes the general report of the professor in charge, E. W. Hilgard, to the president, and four appendices, or special reports: viz., report and discussion of work in the agricultural laboratory, by E. W. Hilgard; report on instruction given, and culture experiments, by Charles H. Dwinelle; report of W. G. Klee, gardener in charge of the experimental grounds, on fruit and miscellaneous cultures; report of work done in the viticultural laboratory, with record and discussion of results, by F. W. Morse.

In his general report, Professor Hilgard reiterates the opinion which he has advanced in another publication (Atlantic monthly, April

...

and May, 1882), that, in view of the present wide-spread indifference to agricultural education, the work of an experiment-station is the key to the situation, so far as the utility and public appreciation of the College of agriculture is concerned." In accordance with this view, work appropriate to an experimentstation has been carried on, in addition to the work of instruction, to as great an extent as the time and means at command permitted; and the four appendices to the general report contain the results of the investigations which have been made.

The work of the agricultural laboratory has consisted chiefly of an examination of the more important and widely distributed soils of the state. These are classified geographically; and chemical and mechanical analyses of several representative samples of each class have been made, from the results of which very important conclusions are drawn as to the present and prospective value and the proper treatment of these soils. Professor Hilgard is far from falling into the old erroneous belief that chemical analysis can be depended upon to show the immediate deficiencies of a soil; but he holds that it may furnish important information as to the amount and kind of reserve matters which it contains, and afford a guide to a rational method of cultivation; and in his hands it certainly seems to justify the claims made for it.

One of the most interesting portions of the horticultural report in appendix III. is that devoted to the vineyard, where are given the results of experiments on grafting the European grape (Vitis vinifera) upon a native Californian species (Vitis californica). The conclusion is reached, that it must be considered definitely proved that the Vitis californica is well adapted as a grafting stock for a large number of the varieties of Vitis vinifera.' The importance of this fact, of course, lies in the greater power of resistance to Phylloxera possessed by the American species. Experiments upon the latter point are now in progress with grafted specimens.

The account of the viticultural work includes some observations on the occurrence and development of Phylloxera, but is chiefly occupied with the results of the experiments on wine-making, which, though still incomplete, and though necessarily executed on a small scale, furnish much valuable information as to the character of the wine to be obtained from different varieties of grapes, and from grapes grown in different regions of the state. They can hardly fail, if continued, to exert a most

beneficial influence on the advance of this industry in California, and may fulfil the hopes of their authors by leading to the establishment of definite and reliable brands of California wines.

The whole report, while dealing largely with

questions of local interest, affords at the same time an admirable illustration of the advantage accruing to agriculture from the application of high scientific attainments to the investigation of its problems.

ASTRONOMY.

The

Semi-diameter of the moon. - Professor H. M. Paul, formerly assistant at the U. S. naval observatory, gives the results of two occultations of the Pleiades group by the moon, observed by himself to determine the occultation semi-diameter of the moon, and also the corrections to the right ascension, declination, and parallax of the moon, these being necessarily involved with the semi-diameter. occultations occurred on July 6, 1877, and Sept. 6, 1879, and were observed with the 9.6-inch equatorial at the Washington observatory. The relative positions adopted for the stars were those of Wolf with proper motions from comparison with Bessel, and the general proper motion of the group as given by Newcomb. The observations of 1877 were poorly placed for a determination of the correction to the semi-diameter, but those of 1879 give a much more reliable result. From the latter (fourteen in all), the resulting correction to Hansen's mean semi-diameter (15' 33. 47) is 1′′. 69 ± 0′′. 12; and the resulting value is, therefore, semi-diameter = 15′ 1′′. 78 ± 0. 12. He gives also the results of Airy's determination from two hundred and ninty-six scattered observations, from 1830 to 1860. From the immersions and emersions at the dark limb, the resulting values are larger by 0.9 and 0.5 than those given by Paul, and, from immersions and emersions at the bright limb, Airy's results are larger by 2.3 and 4".4; while the probable error of a single observation and of the final result is in all cases greatly in excess of those obtained by Paul. Mr. Paul concludes that the best way to observe the actual occultation at the bright limb is to use as high a magnifying power as possible, so as to obtain a decided difference of color between the star and the moon's limb. Neither set of occultations observed by Paul gives any evidence of deviation of the moon's limb from a perfect circle. - (Rep. Wash. obs., 1879, appendix ii.) M. MCN.

ENGINEERING.

-

[1103

Swelled rifle-barrels. - A board of officers, with Capt. Greer as president, has tested a lot of rifles at the Springfield armory to determine the cause of the bulging of the barrel, which occasionally occurs in practice. They find it due to the fact that the muzzle has been stopped by sand, caused by resting the muzzle in wet sand, or in dry sand after the gun has become foul from firing. This arrests the passage of the ball, so that the pressure is increased at the point of swelling. It is curious that sand produced this result where wooden plugs, driven in tightly and swelled by steam, failed to do so. (Ord. notes, U.S.A., no. 238, Feb. 1.) c. E. M. [1104

Strength of explosives. - Gen. Abbot has extended his investigations to tonite, California gun-cotton, and rackarock. The first consists of 52.5 parts of gun-cotton and 47.5 parts of barium nitrate. The second is gun-cotton pulverized, and containing 24

per cent of moisture. The dry gun-cotton analyzed 89.6 per cent insoluble trinitrocellulose and 10.4 per cent soluble gun-cotton. This is 7 per cent above the standard required by the British government. The rackarock is composed of potassium chlorate and nitrobenzol. The substances are kept separate until needed for use, when the chlorate is dipped in the liquid until it has absorbed enough of it. Gen. Abbot found the relative efficiency in a horizontal plane for tonite, as compared with dynamite No. 1, to be 0.81 for the dry compressed state, and 0.85 for the damp uncompressed state, or 0.83 as the average value. thus stands just below gun-cotton (0.87). Rackarock gives 0.86. The California gun-cotton was found equal to the best English. In a note, he calls attention to the spontaneous decomposition of explosive gelatine into cellulose and free nitro-glycerine, with the evolution of nitrous fumes, while in store during the winter and spring. (Prof. papers corps eng., U.S.A., no. 23, add. i.) C. E. M. [1105

It

Composition of steel. Professor Abel has continued his researches on steel; and his experiments with cold-rolled steel of a particular composition confirm the view that the carbon exists in it in the form of a carbide which has the formula Fe,C, or some multiple of that formula. Whether this carbide varies in composition in different descriptions of steel which are in the same condition of preparation remains to be demonstrated; but the preliminary experiments with small specimens of cold-rolled, annealed, or hardened steel, appeared to warrant the belief that the condition of the carbide in the metal is affected to such an extent, by the process of hardening, as more or less completely to counteract its power to resist the decomposing effect of such an oxidizing agent as chromic-acid solution. - (Proc. inst. mech. eng., Jan., 1883.) C. E. M. [1106

Hydric peroxide as a reagent in chemical analysis. A. Classen and O. Bauer find that the great oxidizing power of hydric peroxide may be made available in many quantitative determinations which depend upon oxidation. Roth & Co. of Berlin manufacture a three or four per cent solution, acidified with hydrochloric or sulphuric acid, as may be desired. In an ammoniacal solution, hydric peroxide oxidizes hydric sulphide completely. This reaction affords a convenient and extremely accurate means for the determination of hydrochloric, hydrobromic, or hydriodic acid, in presence of hydric sulphide.

Arsenious sulphide is oxidized completely into arsenic acid and sulphuric acid. A special form of apparatus was devised by the authors for determining sulphur in sulphides. Hydric sulphide was set free by an acid, and carried forward by a current of carbonic dioxide into a tube filled with glass beads. An ammoniacal solution of hydric peroxide was allowed to drop into this tube, thereby oxidizing the hydric sulphide to sulphuric acid, which was drawn out at the bottom of the tube by means of a stop-cock. By this method accurate results were obtained in the analysis of the sulphides of antimony, tin, cadmium, iron, and of baric sulphite and hyposulphite. (Berichte deutsch. chem. gesellsch., xvi. 1061.) C. F. M. [1108

(Organic.)

Derivatives of chinoline. The study of the derivatives of chinoline and their constitution is continued by several chemists. W. La Coste prepared p-nitrochinoline (16) from p-nitraniline, p-nitracetanilide, and glycerine, and p-dimethylamidochinoline from dimethylamido-p-phenylendiamine

and nitrobenzol. o-nitrochinoline was made from o-nitraniline. m-nitraniline gave m-phenanthroline, identical with the product obtained by Skraup (SCIENCE, i. 283). At the same time there was formed an oxyphenanthroline whose constitution may be represented by the following reactions:

HC- CH

HC C

HC

C = CH H

O. Fischer prepared oxyhydroethyl- and methylchinoline by the action of the corresponding alkyl iodides on a-oxyhydrochinoline. In studying the therapeutic properties of the oxychinoline derivatives, it was found that oxychinoline possessed poisonous properties, and that the chlorides of the corresponding hydro-compounds exerted an action similar to that of chinine. B-oxychinoline and certain of its derivatives were examined by C. Riemerschmied. L. Hoffman and W. Königs prepared tetrahydrochinoline by reduction of chinoline with tin and hydrochloric acid. By the action of nitrous acid this substance gave a nitroso-amine (C,H,,N-NO) which formed nitronitrosotetrahydrochinoline

(CH, NO2 H2 (NNO)

when treated with nitric acid. The corresponding hydrazine was obtained by reduction. Indol was one of the products of the dry distillation of tetrahydrochinoline. (Berichte deutsch. chem. gesellsch., xvi. 669, 721, 727.) C. F. M. [1109

AGRICULTURE.

Digestibility of moistened and cooked fodder. - In continuation of earlier researches on this point, G. Kühn has compared the digestibility of three samples of hay and three samples of wheat-bran, when fed dry, to that of the same fodders variously treated. Moistening the hay or bran immediately before feeding with a quantity of cold water insufficient to satisfy the thirst of the animals (steers) had no recognizable effect on the digestibility. Moistening the bran with cold water twenty-four hours before feeding had no effect on its digestibility, provided the quantity of water was so limited that the amount drunk by the animals did not fall below about fifty per cent of that drunk when the ration was given dry.

When the amount of water used to moisten the bran largely exceeded the limit just mentioned, indications of a decreased digestibility of the crude proteine of the total ration were observed. Treating the bran with boiling water twenty-four hours before feeding caused an undoubted decrease in the digestibility of its crude proteine, which was greater the higher the initial temperature, and the longer the action of the heat continued. The other constituents of the bran were unaffected. Giving the bran stirred into water as drink, along with dry hay, had no noticeable effect on the digestibility of the total ration, compared with that observed when similarly prepared bran was mixed with the hay. The experiments gave also the interesting and important result, that the extent to which the same fodder is digested by the same animal may vary at different times. A new source of error in digestion experiments is thus brought to light, and one which must receive serious consideration in all future experiments, and lead to new caution in accepting the results of old ones, especially in the case of concentrated fodders, since the calculation of the digestibility of the latter is based on the assumption of unaltered digestibility of a coarse fodder for two consecutive periods. These experiments are worthy of notice also for the care and conscientiousness with which the limits of possible error are taken account of in the discussion of the results. They afford, in this respect, an excellent example of really scientific investigation, and contrast favorably in this particular with many agricultural experiments. - (Landw. vers.-stat., xxix. 1.) H. P. A. [1110

Bottled milk. - Milk preserved by Scherff's process (heating in closed bottles to 100°-120° C. for one or two hours) differs from fresh milk in certain respects. It is not coagulated by rennet, and when acidified, or allowed to become sour, it yields a fine, granular coagulum. These differences have been attributed to chemical changes in the albuminoids of the milk, produced by the heat; but Fleischman and Morgen fail to find in such bottled milk any peptones or other products of the decomposition of proteids, or any evidence of a chemical alteration. It appears to be a trifle less readily acted on by pepsin than fresh milk. The good results obtained by its use for sick children are ascribed to the granular coagulum which it yields in the stomach, and its freedom from all germs. (Landw. vers.-stat., xxviii. 321.) H. P. A. [1111

Soil-temperatures. In continuation of previous researches, E. and H. Becquerel have taken the temperature of two soils at different depths twice daily during the year 1882. One soil was naked, and the other covered with turf.

At a depth of 0.05 m., the turfed soil was the warmer at 6 A.M. At 3 P.M. the naked (sandy) soil was the warmer during the warm months, while during the cold months the reverse was the case: in other words, the range of temperature was less under the turf. At greater depths this effect became less marked, and on the average the turfed soil was 0.10-0.7° warmer than the naked one. (Comptes rendus, xcvi. 1107.) H. P. A. [1112

the fermentation, and smaller quantities of ammonia, nitrous oxide, nitric oxide, nitrites, and probably amide-like bodies, were obtained. The action has been shown to take place in soils rich in organic matter, when excluded from the air; and a small quantity of active soil may infect a large amount of soil which has been sterilized by heat. (Bied. centr.blatt, 1883, 82.) H. P. A. [1113 Butt and tip kernels of corn. In a number of sprouting trials at the Ohio agricultural experiment-station, corn taken from the butts of the ears produced larger and stronger radicles than that from the tips, while that from the middle of the ear was intermediate in this respect. The proportion of seeds which sprouted was: tip kernels, 70.3 %; middle kernels, 58.2 %; butt kernels, 76.1 %.-(Country gentleman, May 10.) H. P. A. [1114

GEOLOGY.

The Balkan peninsula.- In the tenth number of Petermann's mittheilungen for 1882, Toula published a geological map of this region, which gives us a better idea of the geology of that much-disputed country than any thing yet published. By a mistake, the region between Aiwadschik and Köprüköï, in Bulgaria, was colored as Jurassic instead of eocene. With this exception, this map, in sixteen colors, is fully up to Petermann's usual standard. Toula now publishes a map on the scale of 1: 2,500,000, on which, by means of twenty-five different lines, he shows the routes travelled over by different geological explorers in this region from the days of Herder, Boué, and Viquesnel (1835-37), down to the present time, and in the accompanying ten pages of text gives a brief account of the country visited, and a historical sketch of the work done by each author. – (Mitth. geogr. gesellsch. Wien, 1883, 25.) J. B. M.

[1115

Origin of the carboniferous limestone of Belgium. - Dupont divides the carboniferous limestone of Belgium into massive and stratified limestones, the latter essentially detrital rocks with a sedimentary appearance. The massive limestones are due to the growth of corals, and are adapted to the special dispositions of coral formations in fringing reefs or islets, according to their distance from the shore. The detrital limestones are subdivided into two marked categories: the crinoidal limestone; and the limestone made up of coralline detritus, with or without interstratified beds of crinoidal limestone. These three divisions correspond with the three faunas that de Koninck has distinguished, the fauna

of Tournai, belonging to the crinoidal limestone; the fauna of Waulsort, to the coral-reef limestones; and the fauna of Visé, to the detrital limestones. The stratigraphical study of the Belgian carboniferous limestone thus becomes much simplified; and the problems suggested by the mixture of rocks of the same chemical composition, but of different modes of formation, can be solved by studying the mode of formation, and the application of the stratigraphical laws of coral phenomena established by the study of the Devonian limestones. (Bull. acad. roy. Belg., (3), v. no. 2.) J. B. M. [1116

PHYSICAL GEOGRAPHY. Causes of the fertility of land in the Canadian north-west territories.-Robert Bell showed, that, with local exceptions, a vast fertile tract stretches from the Red River valley to the Liard River, a distance of some fourteen hundred miles, characterized by a dark loamy soil of varying depth and nearly

homogeneous consistency. The primary cause of the fertility of this region may be found in the character of the subsoil, which consists largely of cretaceous marls and the comminuted material of the glacial drift. The speaker ascribed to moles and other burrowing animals the chief agency in the process by which the black loamy soil was formed out of this subsoil. Darwin had proved that in England and some other countries earth-worms played the chief part in the formation of mould. These worms appear to be absent in the north-west, as well as in most cold and sparsely settled countries, perhaps due to the depth to which frost penetrates. But in the north-west he believed the ground squirrels and moles more than made up for the absence of worms. In the fertile area referred to, the old and new mole-hills cover the entire surface, rendering it 'hummocky,' as is easily observed after a prairie fire. These animals are very active in autumn, digging many more burrows than would appear to be of any use to them. Each hummock thus thrown up covers about a square foot, and buries all the grass, etc., on this space. In this manner large quantities of vegetable matter were ultimately incorporated with the soil, which was also refined by the fact that the stones and coarse gravel are left undisturbed below the surface, so that in time they are more deeply buried by the layer of mould produced. By an interesting coincidence at the season when these burrowing animals are most active, the prairie vegetation is mature, and contains the greatest amount of substance. The coldness of the soil during a great part of the year tends to preserve the organic matter in it. While the circumstances given were the direct cause of the fertility, the ultimate reason was perhaps to be looked for in the climate, which fosters the growth of such vegetation as forms both the fertilizing material and the food of the little workers, who mingle it with the mineral portion of the soil. The action of frost in comminuting the soil does not account, by itself, for the introduction of the organic matter upon which its fertility depends, and which is due to the co-operation of the circumstances and agencies described. (Royal soc. Canada; meeting May 23.) [1117

The French 'Landes.'-E. Blanc describes the great improvement effected in the formerly desert region of south-western France by planting its sandy surface with the maritime pine (Pinus pinaster). The region is divided according to its surface-features into five districts, locally named the GrandeLande, the Dunes, the Marensin, the Maremme, and the Chalosse. The first includes half the entire area, and, before the tree-planting, was an open plain of loose sandy soil about two feet deep, lying on an impermeable layer (alios) of sandstone cemented by organic and ferruginous material. During winter it was a great marsh; in summer, a dry, sandy desert, barely supporting its flocks of sheep. The absence of stone for building and road-making was another cause of its poverty. Since 1857, nearly the whole surface has been covered with a continuous pine forest, from which the resin is a valuable product. The stilts of the old shepherds are no longer the fashion. The Dunes, extending along the coast of Gascony from the Adour to the Gironde, form a belt four to eight kilometres wide. Their sand does not come from the coasts of Spain and Brittany, as has been supposed, but from a submerged continuation of the Landes. Their height sometimes reaches eighty metres. These, also, were formerly barren: they are now almost entirely wooded over. Their area of 88,096 hectares (nearly 350 miles) contained 15,82