CHEMICO-PHYSIOLOGICAL EXAMINATION OF ICELAND MOSS (CETRARIA ISLANDICA).

BY DR. G. SCHNEDERMANN AND DR. W. KNOP.

THE authors describe this lichen as being composed of three laminæ, as follows:

1. The inner layer of globular cells.-These cells contain the green colouring matter of the lichen, which differs from chlorophylle, and is called by the authors thallochlor.

2. The layer of branching larger cells.—This layer is colourless. Under the highest magnifying power nothing can be detected within the cells. This layer supports and nourishes the inner layer of globular cells.

3. The most external and finely cellular cortical layer.-This layer contains in its intercellular spaces the lichen starch. If hydrochloric acid be applied to a section of the cortical layer, the lichen starch swells up into many times its original volume. This layer no doubt also contains cetraric acid (formerly called cetrarin).

The authors submitted Iceland moss to a careful chemical analysis, and have described, in a very detailed manner, their modes of procedure. They then successively notice the more remarkable chemical constituents of the lichen, viz. thallochlor, cetraric acid, lichestearic acid, an unnamed substance, which is provisionally called the body C, and lichen starch.

1. Thallochlor.-This substance constitutes the green colouring matter of the globular cells before noticed. Its ethereal solution is of a beautiful green colour. Thallochlor has the properties of a weak acid and combines with bases. An alcoholic solution of acetate of lead occasions, with an alcoholic solution of thallochlor, an abundant flocculent green precipitate, which when separated by filtration, then boiled with ether, and decomposed by acetic acid, yields the thallochlor as a brittle and pulverizable mass, which is distinguishable from chlorophylle by its being little, if at all, soluble in hydrochloric acid.

2. Cetraric Acid.-This acid, formerly called cetrarine, forms a loose tissue of shining minute acicular crystals. It is intensely bitter, not volatile, and is infusible without decomposition. It is almost insoluble in water, which, however, acquires a bitter taste when boiled with the acid. It is soluble in boiling alcohol, but crystallizes in great part on cooling. It is slightly solu ble in ether, and quite insoluble in the fixed and volatile oils. Its composition is C3 H16 015. It is dissolved by both the caustic and carbonated alkalies, and is precipitated from its solution by acids. Cetrarate of ammonia (2 NH3+C4 H16 O15) is a beautiful yellow salt, having a faint ammoniacal odour and being soluble in water. Cetrarate of lead (2 Pbo+C H16 O15) forms a yellow flocculent precipitate.

3. Lichestearic Acid. The name of this acid is derived from λexyv, lichen, and σreap (fat). When pure it is perfectly white, and forms a loose mass composed of crystalline pearly plates. It is odourless, but has an acrid taste. It is soluble in alcohol, ether, and the volatile and fatty oils; but is insoluble in water. At 248° F. it melts, and on cooling congeals into a crystalline mass. It cannot be volatilized without decomposition. Its composition is C20 H25 O6. It is dissolved by alkalies, and is precipitated from its alkaline solution by acids. Lichestearate of potash is a white indistinctly crystalline powder. Lichestearate of silver (AgO+C20 H24 Os) is grayish white. Lichestearate of lead (PbO+C20 H24 Os) is white also. Lichestearate of baryta is grayish white. Lichestearate of ammonia is crystallizable.

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4. The substance provisionally called the body C."-This substance is found in the lichen in tolerable quantity. It is white or yellowish, without

either taste or smell, insoluble in water, ether, oils, alkalies, and acids, and difficultly soluble in spirit of wine. It is decomposed by heat, leaving 0.2 to 0.3 per cent. of ash. Two analyses gave in 100 parts,

By ignition with soda-lime it yielded 0.51 per cent. of nitrogen.

5. Lichen starch,-When the pure lichen is treated with concentrated hydrochloric acid it is converted into an homogeneous mucus. This is treated with water and then separated from the residual lichen by straining it through a woollen cloth. The liquor thus obtained was divided into two parts, to both of which spirit of wine was added until a cloudiness was produced. To, one part was further added about one-third of its volume of spirit of wine, by which white flocculi were precipitated. This precipitated liquid was then mixed with the other part of the filtered liquor, and the mixture well shaken and then poured on a stretched woollen cloth. The filtered liquor had the colour and transparency of white of egg, and yielded, on the addition of spirit of wine, a flocculent precipitate, which when collected on a hair sieve and dried presented the usual quantities of boiled and dried starch. If, on the other hand, the muriatic extract be immediately precipitated by spirit of wine, and the precipitated mass washed and then boiled with dilute spirit, the substance separated by filtration does not yield a blue colour with iodine, and possesses the properties which Mulder has assigned to lichen starch.--Ann. der Chemie und Pharm, Band. Iv.

DR GOUDRET'S AMMONIACAL BLISTERING_OINTMENT. THE following improved formula for this application is recommended by the author in preference to that which has hitherto been in use ;→ (

Take of Lard......

Oil of Almonds

..32 parts

2

Melt the lard with the oil by the application of a gentle heat; pour them in the melted state into a wide-mouth bottle, and add

Solution of Ammonia .........17 parts

Mix, by continual agitation, until it becomes cold. It is necessary to avoid the application of much heat in the preparation of this ointment. When well prepared it will produce vesication in about ten minutes, and will retain its properties unimpaired for about a month, if kept in a well stopped bottle.--Journal de Pharmacie.

NOTICES OF BOOKS.

THE DUBLIN QUARTERLY JOURNAL OF MEDICAL SCIENCE. New Series, No. 1, February, 1846. Dublin: Hodges and Smith, Grafton Street. London: Longmans and Co.; Simpkin and Co.; W. Orr and Co. Edinburgh; Maclachlan, Stewart, and Co.; and Sutherland and Knox. Glasgow: David Chambers. 8vo, pp. 276.

Tuis journal, which has flourished from the year 1832 until the present time, during which period twenty-eight volumes have been published, has now assumed a new and enlarged form. Its pages are devoted to Medical and Surgical Science in all

branches, including Chemistry, Materia Medica, and Botany; "unconnected with medical politics, and uninfluenced by party feeling, jealousy, or personal hostility." No. 1 of the new series contains a preface of forty-eight pages by the Editor, in which is given a very interesting summary of the progress of medical science in Ireland during the last two centuries, with a notice of the scientific societies and periodicals which have been established.

Most of these societies were rather limited in the number of members, and some of them were of a social character, or scientific clubs. They all contributed, more or less, to the advancement of science, and, in some instances, corresponded with the Royal Society of London, and other scientific bodies, both in this country and on the Continent.

The first medical periodical started in Ireland was a quarterly journal of about 100 pages, which was undertaken in 1807, entitled The Dublin Medical and Physical Essays, comprising Dissertations and Details of Medicine and Surgery, with their collateral Branches of Science. It survived only eighteen

months.

The first number of the Dublin Hospital Reports and Communications in Medicine and Surgery, appeared in 1815-the fifth and last in 1830. Contemporaneously with this periodical was published The Transactions of the Association of the Fellows and Licentiates of the King's and Queen's College of Physicians, Ireland; five volumes of which appeared at intervals up to 1828. In 1830 a new series was commenced, entitled The Dublin Medical Transactions. The Dublin Philosophical Journal and Scientific Review, which came out under favour

able auspices in 1825, was not successful, and was succeeded by a monthly journal edited by Mr. Donovan, entitled The Annals of Pharmacy and Materia Medica, the chief object of which was the "improvement of the science of Pharmacy and the condition of the Apothecaries." This journal contained severe strictures on the "so-called monopoly of the Apothecaries' Corporation," and was rather political in its character. It was discontinued after the twelfth number.

In March, 1832, appeared the first number of the Dublin Journal of Medical and Chemical Science, the subject of this notice. The original projector and first editor, Dr. Robert Kane, devoted his chief attention to Chemical and Pharmaceutical subjects, merely including Medicine and Surgery, as collateral branches. But shortly afterwards the journal became more extended in its character, and has continued to enjoy a high reputation as a scientific periodical.

The Dublin Medical Press, a stamped weekly Medico-Political Journal, appeared in 1839, and is now flourishing; during the past year The Dublin Hospital Gazette has been established.

We have been much interested in reading the account of the above institutions and literary productions; and it is satisfactory to observe the increasing disposition which prevails both in England and in Ireland, to encourage and support undertakings of this description.

London:

THE LITERARY AND SCIENTIFIC REGISTER AND ALMANACK, for 1846. By J. W. G. GUTCH, M.R.C.S., &c. Simpkin, Marshall, & Co.

We regret that we accidentally omitted to notice this little book at the beginning of the year. It is (as we have observed of its predecessors for the last four years) the most complete and useful pocket-book we have seen, and contains a great variety of information in a very small space. The table of contents occupies six closely printed columns.

THE HALF-YEARLY ABSTRACT OF THE MEDICAL SCIENCES; being a Practical and Analytical Digest of the contents of the principal British and Continental Works published in the preceding six months; together with a Series of Critical Reports on the Progress of Medicine and the Collateral Sciences during the same period. Edited by W. H. RANKING, M.D., Cantab., Physician to the Suffolk General Hospital. Vol. ii. 8vo., pp. 448. London: John Churchill, Frinces Street, Soho. Edinburgh: Maclachlan and Co. Dublin: Fannin and Co.

THE CHEMIST'S COUNTER COMPANION, OR COMPLETE RETAIL PRICE BOOK, compiled for the Leicestershire Association of Chemists and Druggists. By JOSEPII GODDARD. Leicester: J. Burton, Mercury Place. Small 8vo. pp. 208.

THIS price-book is adapted for the use of Chemists in general, and its arrangement is judicious and convenient. The articles are classified according to the preparations, the extracts, tinctures, pills, barks, woods, oils, &c., &c., being each class respectively arranged in alphabetical order. This plan is more convenient than that of distributing each class of preparations over the whole book-for instance, under the head Rhubarb, enumerating root, powder, tincture, syrup, pill, &c. in the same page, which creates confusion. There are columns for the price per pound, quarter pound, and ounce retail, a column for wholesale price, and another for cost price. There is also a column for the place in the shop where each article is kept. In using this column, it is proposed to divide the shop into imaginary compartments, labelled A, B, C, &c., the articles in each compartment being numbered. We have for some time past felt the want of a complete and well arranged price-book, and the one before us is calculated to supply this deficiency.

TO CORRESPONDENTS.

D. E. C.-The term paregoric is derived from a Greek word, signifying to mitigate, or to assuage. Calomel is said to be derived from two Greek words signifying good and black; there is some difference of opinion as to the origin of the application of the term. Verdigris is probably derived from the French name vert-de-gris, indicating its colour.

M. P. S.-(1.) We know of no better way of making silicate of lime than fusing the ingredients together.-(2.) No.

A CORRESPONDENT.-Nitrite or hyponitrite of soda is obtained by heating nitrate of soda to redness, and removing it from the fire before the decomposition is complete.

B. L. L. H.-We believe oil of worm-seed is not known in this country as an article of commerce. An oil may be obtained by distillation.

J. A.-See vol. v., No. 3, page 110 (valerianic acid).

“A SEEKER OF INFORMATION.”—In the process of the Pharmacopoeia for making syrupus papaveris, the ripe capsules of the poppy are directed to be used, and we should understand this to include the seeds. The shell only would be more properly described as the pericarp.

E. A. P. S.-The addition of a little liquor potassæ, or chloride of calcium, would probably remedy the defect alluded to.

"INQUISITOR."-We believe Indian ink is the kind best adapted for pen and ink sketches.

P. Q. R.-Cachou Aromatisé, see vol. iii., No. 4, page 91, and vol. v., No.8, page 380.