diluted with sugar of milk, so that it will be of such strength that 1 gr. will dissolve 300 grs. of coagulated albumen.

Mention some of the products resulting from the action of ferments (including the organized ferments).

All of the crude alcohols, such as wine, whiskey, brandy, acetic acid, etc., the by-products, cream of tartar and tartaric acid (from organized ferments).

Oil of bitter almonds and oil of mustard are the result of unorganized fermentative action.

In making citric acid, fermentation is employed.
NOTE. For further details, see substances named.

CYANOGEN COMPOUNDS.

What is the composition and properties of cyanogen? Cyanogen (CN) as met with in compounds is a univalent radical, and behaves chemically like the halogens. The gas (CN), is very irritating to the eyes and air passages, and possesses a penetrating odor like bitter almonds.

What compound is formed with Cy and H?

Hydrocyanic, or Prussic Acid, HCN or HCy.

Name two methods of manufacture of this acid and its strength.

It is made first by decomposing ferrocyanide of potassium with H,SO,, thus:

two per cent. of absol acid.

Hydrocyanic

Acid.

Second by decomposing AgCy by means of HCl. Strength

What other substances contain HCN?

Bitter almonds, wild cherry bark, and the kernels of the peach and plum, etc.

Does HCN pre-exist in bitter almonds and wild cherry, etc.?

No; it is formed by the action of two substances, known as amygdalin and emulsin (the former does not exist in sweet almonds); this action takes place when these substances are brought in contact with water, and is found associated with the volatile oil (oleum amygdala amaræ). (See also Ferments.) What cyanogen compounds are found in oil of mustard?

Crude oil of mustard often contains cyanide of allyl, C3H5CN.

The oil of white mustard is known as sulphocyanate of acrinyl (C,H,OCNS), and the oil of black mustard the sulphocyanate of allyl (C2H¿CNS).

Explain the formation of this oil.

The white mustard seed contains sinalbin, a glucoside which, in contact with myrosin, a ferment, produces the oil of white mustard.

The black mustard contains sinigrin and myrosin, which, like the former, under the influence of moisture and consequent fermentation produces the pungent volatile oil.

Animal Drugs.

Name the official animal drugs and their products which have not been previously mentioned.

Cantharis, Coccus, Fel Bovis (inspissated and purified oxgall), Moschus, Sevum, Vitellus, Adeps, Ichthyocolla, etc. Name some of the active constituents found in the above drugs.

Cantharis (cantharidin), Coccus (red coloring matter, wax and fat), Moschus (ammonia, cholesterin, fat), Sevum (stearin and palmitin), Vitellus (albumen vitellin).

What is the official name and composition of lanolin?

Adeps Lane Hydrosus. Hydrous Wool Fat: The purified fat of the wool of sheep mixed with not more than 30 per cent. of water.

Alkanin, soluble in ether, alcohol, fats and certain volatile oils, alkalies change to blue; for coloring tinctures or pomade.

Rubia (Madder) contains Ruberythrin (yellow needles, blood-red with alkalies), Alizarin (orange-red needles, purple or blue with alkalies), Purpurin (red needles, violet-colored with alkalies).

Crocin, insoluble in ether, soluble in alcohol, colored blue by H2SO1.

Curcumin, orange-yellow, insoluble in water, soluble in alcohol and ether, red-brown with alkalies and boric acid.

Cambogic acid (soluble in alcohol and ether, colored blackbrown by ferric chloride; soluble in alkalies with a red color).

Hæmatoxylin, colorless, sweet, soluble in water and alcohol, red in sunlight purplish by alkalies.

Hæmatin (a product of the above), green metallic lustre, soluble in alkalies with blue color.

Litmus, blue; red with acids.

Quercitrin (in rosa gallica and quercus tinctoria), yellow crystalline, nearly insoluble in cold water, colored dark green

by ferric salts (an infusion of rosa gallica by dilute acid is colored red).

Sanguinarine, white, soluble in alcohol, ether and benzol, yields bright red salts.

Santalic Acid, red needles, soluble in ether with a yellow, and in alkalies with violet color; pterocarpin and santal, colorless, insoluble in water; the solution of the latter in alkalies turns red and green.

DISPENSING-INCOMPATIBILITY.

DEFINED. That condition in which there exists either α chemical change" or decomposition, a therapeutical opposition of constituents, or a mechanical dissociation of constituents (the latter may be termed pharmaceutical incompatibility). CHEMICAL INCOMPATIBILITY.-Where chemical change results.

THERAPEUTICAL INCOMPATIBILITY.—Where there is antagonism in physiological action.

PHARMACEUTICAL INCOMPATIBILITY.-Where there is dissociation of constituents, resulting, it may be, from quality of ingredients or from violation of correct pharmaceutical procedure.

REMARKS.—A prescription may be chemically or pharmaceutically incompatible and be compatible therapeutically, because it furnishes just what the physician demands. (Ex., ZnSO4 + Pb (C2H2O2)2 + Aq,— Injection.)

A PRESCRIPTION IS ABSOLUTELY INCOMPATIBLE when the chemical or pharmaceutical incompatibility sustained defeats the object of the physician, producing new products having totally different therapeutic effects than those obviously intended.

The intended therapeutic action is therefore the basis of final decision as to whether the pharmacist shall or shall not decline or hesitate to compound a prescription.

Incompatibility, embraced as it is within the foregoing propositions, seems quite comprehensible; but we must remember that there are a vast variety of combinations possible in prescription compounding, and while incompatibility is not a formidable subject, it becomes complicated when we consider that almost every new prescription is largely a law unto itself until tried. Therefore, expertness in pharmaceutical manipulation, of which prescription work is the highest type, becomes a matter of individual ability, and can only be acquired in the largest and best measure by personal experience. To be expert, however—to be able to detect any deviation from the right standard and solve the multifarious puzzling problems— requires first, the knowledge and realization of the truths of the fundamental principles laid down, and a clear understanding of the chemical and pharmaceutical properties of medicinal substances.

ARRANGEMENT OF INCOMPATIBLE SUB

STANCES.

In using the following table, it is only needful to remember the well-known chemical law that if a solution of a compound be brought in contact with a solution of another compound, and by an interchange of radicals an insoluble compound be produced that compound is precipitated.

Acetates are soluble.

Arseniates are insoluble, except those of the alkali metals. Arsenites are insoluble, except those of the alkali metals. Bromides are soluble, except mercurous and silver; those of antimony and bismuth are decomposed by water to form oxysalts. Carbonates are insoluble, except those of the alkali metals. Chlorides are soluble, except those of lead (s),* mercurous and silver.

* Sparingly soluble (s).