Proceeding in this way, barbaloin readily yields more than a third of its weight of pure potassic chrysammate.

Chrysammic Acid.-Crystals of chrysammic acid are best obtained by dissolving potassic chrysammate in a considerable quantity of boiling water, and strongly acidifying the liquid with acetic acid. Thin yellow fern-leaves, a quarter of an inch long, mixed with a few long red crystals, are deposited in a few hours. On warming the whole gently, the latter are redissolved, and the yellow fern leaves which are mixed with a few much smaller tables may be filtered off and washed. They consist of pure chrysammic acid; in mass they strongly resemble picric acid, but are more lustrous.

After exposure to dry air at ordinary temperatures for a few days, they suffer no loss of weight by heating to 150° C. Evaporated with pure sulphuric acid, they leave no residue.

Lead Chrysammate.-Described by Schunck and Mulder as a red powder containing variable proportions of lead. It may easily be obtained, however, beautifully crystallised, by mixing a boiling solution of potassic chrysammate with a slight excess of plumbic acetate dissolved in boiling water and acidified with acetic acid. On cooling, long thin prisms, exhibiting a magnificent bronze reflection, are formed. The light transmitted by the crystals is pale red and strongly polarised, so that on viewing, by means of a lens, some of them suspended in the mother-liquor, the light is seen to be completely cut off, when two of them cross each other at right angles. Mounted properly, they form a pretty microscopic object. The salt was found to have the formula C14 H2 Pb" (N O2)4 04 · 4 H, O.

2

Barium Chrysammate.-Hitherto described as a red powder. Obtained in the crystalline form by mixing boiling solutions of potassic chrysammate and barium chloride acidified with acetic acid. It appears to be one of the most insoluble of the chrysammates, as the mother-liquors left after the crystallisation of the salt are almost colourless. It forms brown shining needles, which, however present none of the green or golden lustre so noticeable in most of the other salts.

The formula seems to be the same as that assigned by Mulder to the uncrystallised compound, viz., C14 H2 Ba" (N O2)4 04 2 H2

0.

Potassium Chrysammate crystallises in two forms; usually as dark red spangles with bright green lustre, or when the salt is crystallised quickly, or from a slightly acid solution, as bright crimson needles with slight golden reflection. The red crystals have the formula C14 H2 K2 (N O2)4 04. 3 H2 O.

2

The formulæ used in this paper are double those hitherto employed for chrysammic acid and its compounds, and are in accordance with the view of Graebe and Liebermann, who represent chrysammic acid as a derivative of anthrakinone. On this supposition it must be a dibasic acid, and I have therefore made some attempts to prepare some salts, the constitution of which might help to decide this question. At present, however, I have not been successful in producing acid or double salts, presenting characters such as would entitle them to be pronounced definite compounds.

=

New Acid from Aloes. P. Weselsky. (Deut. Chem. Ges. Ber., v., 168. Journ. Chem. Soc., 2nd series, x., 489). Aloes treated by Hlasiwetz's process (fusion with caustic potash) yields, in addition to orcin and paroxybenzoic acid, a small quantity of new acid, alorcinic acid C, H10 Og. This acid, which is obtained from the mother-liquors of the paroxybenzoic acid, is crystalline, and dissolves with difficulty in cold water, but readily in boiling water, in alcohol, and in ether; by dry distillation it forms a crystalline anhydride; ferric chloride gives no coloration with its aqueous solution, but the liquid when alkalified gradually becomes cherryred; hypochlorites give a beautiful purple-red, destroyed by excess of reagent; neutral lead acetate gives no precipitate, but the basic acetate gives a white precipitate becoming red by exposure to air. Fused with caustic potash it forms acetate and orcin—

C9 H10 O3 + H2O = C, H, O2 + C2 H4 O2.

8

Thence the author concludes that it is isomeric with acetyl-orcin, and has the formula

Gelatiniform Matter, Albuminose, Exalbumin, Galactin. Antoine Morin. (Journ. Pharm. Chim., 4th series, xiv., 11.) The albuminose described by Mialhe and the exalbumin of Corvisart are believed by the author to be identical with the gelatiniform matter discovered by him in 1842. He now finds that it can be obtained most abundantly from milk, and hence proposes to abandon the names formerly given to it, and adopt the name galactin.

Galactin constitutes about three per cent of dried milk. Το obtain it, the casein is separated by acetic acid, the albumin by boiling, and the fat removed by ether. The liquid is then concentrated, filtered from phosphates, and the sugar crystallised out. On

adding alcohol the galactin is precipitated in the form of a gelatinous mass which contains a little gelatin.

Galactin is soluble in water, insoluble in alcohol and ether, and is not transformed into gelatin by the prolonged action of boiling water. Like gelatin it is precipitated by tannin, but the precipitate redissolves upon the application of a gentle heat.

Galactin is found in the blood, the gastric juice, the membranes, the liquid of the foetal cotyledons, milk, and eggs. It also frequently appears in fluids generated by disease. It also occurs in vegetable juices and is probably as generally distributed as albumin.

Some Properties of Egg Albumen, M. A. Petit. (Journ. de Pharm., 4th series, xiii., 14.) The author shows that the albumen of white of egg undergoes a change of properties by the action of dilute acids. He prepared a liquid composed of one-tenth of white of egg and nine-tenths of distilled water; this solution after filtration is perfectly transparent, and is not troubled by the addition of potash or ammonia. It is slightly troubled if the free alkali it contains is neutralised. If a dozen drops of concentrated acetic acid are added to 10 cubic centimetres of this solution, it becomes precipitable by potash but not by ammonia. On boiling the acidulated liquid it remains perfectly transparent, and becomes precipitable not only by potash but also by ammonia. These modifications are accompanied by a change in the power of deviating the plane of polarisation. The primitive ten per cent. albumen solution rotated 2 degrees to the right, and 7 degrees after ebullition with the acetic acid.

The addition of alkalies to the heated acetic liquid, precipitates all the albumen before saturation of the free acid is attained. The neutralisation of one-sixth of the free acid determines the total precipitation of the albumen.

A similar change in the albumen, accompanied with augmentation of the rotary power, is produced by alkalies. Adding one gramme of caustic potash to 75 cub. cent. of the ten per cent. albumen solution, and saturating immediately with acetic acid, the total precipitation of the albumen is obtained without the intervention of heat. Two estimations effected, the one by this process and the other by saturating the natural alkali and boiling, gave concordant numbers. The albumen of urine has not yet given the author the same results. He states that animal charcoal has the power of absorbing albumen from solution in liquids which are either neutral, acid, or alkaline.

M. Gautier, in some remarks on this paper, states that the

albumen of white of egg is composed of two distinct albumens, the one having its maximum point of coagulation at 63°, the other at about 74°. The proportion of these albumens is as 1 to 5. The first has a rotary power of 43.2°, the second of about 26°, the latter number being subject to some reserve. White of egg contains in addition, a caseic substance and lactoprotein.

Fundamental Difference between the Structure of Albumen and that of Caseine. J. Alfred Wanklyn. (Pharm. Journ., 3rd series, ii., 66.) Among the determinations of the quantity of ammonia evolved by the action of alkaline permanganate of potash on organic substances, Chapman, Smith, and myself, have already published that caseine yields 76 per cent. of ammonia, and that albumen yields about 10 per cent. We considered, however, that a result of such importance required confirmation; and refraining from drawing the conclusions legitimately following from it, pointed out that in the instance of the caseine taken for our experiment some further guarantee was desirable. Confirmation has been given; caseine having been shown to yield 6-5 per cent of ammonia, rather less than before, and consequently even further removed from albumen than was at first represented.

In ultimate percentage composition albumen and caseine are indistinguishable. In oxidation products they have, up to the present time, been considered as being alike. Only in some small reactional characters, as, for instance, that the one is, and that the other is not, precipitable by acetic acid, had they been distinguished. The difference in the yields of ammonia, which we now insist upon, points to deep-seated difference in chemical structure, and shows that albumen and caseine, which are metameric, and possibly even isomeric with one another, belong to different chemical families.

Inasmuch as the albuminous compounds of young mammals have necessarily been obtained by metamorphoses of the caseine supplied in the milk which they feed upon, the process of assimilation must consist partly in fundamental chemical change, and not merely in morphological changes and superficial chemical alterations.

A Blue Colouring Matter in the Bile. E. Ritter. (Pharm. Journ., Feb., 1871, part xx., p. 688.) Städeler and Jaffé have shown that a blue colouring matter can be obtained by the action of nitric acid on the biliary pigments. Ritter describes a blue colouring matter, which he regards as a constituent of the bile, and not as a product of chemical action. He finds it in the bile of man, the ox, the sheep, the pig, the dog, and the cat. It is prepared as follows:

Bile is shaken with chloroform till a yellow solution is obtained, and the yellow chloroform solution is treated with soda till the colour entirely disappears. On neutralisation with hydrochloric acid two layers are formed, one of which contains the yellow chloroform solution, the other the blue colouring matter in a state of suspension. The colouring matter is insoluble in chloroform and acids. It dissolves in alkalies, forming a colourless or yellowish solution. When this solution is neutralised with acids and exposed to the air, à brown precipitate forms, which after a few days, but sometimes only after a month, again becomes blue. Reduced indigo, on the other hand, dissolved in alkalies, becomes instantaneously blue on exposure to the air.

Occurrence of Chondrigen in the Tunicata. Dr. Schäfer. (Ann. Chem. Pharm., clx., 330-333. Journ. Chem. Soc., 2nd series, x., 309.) Dr. Schäfer, at the suggestion of Dr. Hilger, who had found chondrigen in the Brachipoda and Holothuridæ, investigated its occurrence in the tunicata. By boiling the mantles for some time in a Papin's digester, an opalescent solution was obtained, which, however, could not be got to gelatinise. It was precipitated by acetic acid, insoluble in excess, by basic and neutral lead acetate and voluminously by alum. Tannin caused no turbidity or precipiTo avoid error from the presence of substances used in precipitating it, the nitrogen amount was determined from the residue left on the evaporation of the watery solution after treatment with dilute hydrochloric acid, and washing with alcohol and water. amount found was 14.99 per cent., which agrees essentially with that of chondrin as given by Scherer, Mulder, and Vogel, A more complete elementary analysis was impossible from deficiency of

tate.

material.

The

Preparation of Pepsin. Dr. L. S. Beale. (Med. Times and Gazette, 1872, i., 152.) In the "Year Book," 1871, we noticed a communication by Professor Beale, on the means of obtaining pepsin by drying the mucus expressed from the stomach glands. During the present year the author has given the following details of the process :—

The mucous membrane of a perfectly fresh pig's stomach was carefully dissected from the muscular coat, and placed on a flat board. It was then lightly cleansed with a sponge and a little water, and much of the mucus, remains of food, etc., carefully removed. With the back of a knife, or with an ivory paper-knife, the surface was scraped very hard, in order that the glands might be squeezed, and their contents pressed out. The viscid mucus