c.c. of the liquid examined, in a retort of 60 c.c. capacity, with 2 grams of powdered bichromate, 15 c.c. of water, and 25 drops of sulphuric acid-digesting fifteen minutes and then distilling 15 c.c.

f. In the distillation of methylic alcohol, add a little animal charcoal and a little solution of sodic carbonate, and receive the distillate at 66° to 76° C. (151° to 169° F.)

Quantitative.-g. Place in a retort 55 grams crystallized oxalic acid and the mixture of 35 grams of concentrated sulphuric acid and 25 grams of distillate f, digest for ten hours, and distil from an oil-bath at 160° to 180° C., as long as anything passes over. The distillate consists of oxalic ethers; methyl oxalate being freely soluble in water, while ethyl oxalate is nearly insoluble. The distillate is now washed with 25 times its volume of water; the clear solution decanted, digested, in a close bottle, with excess of potassa, the mixture acidulated with acetic acid and precipitated with calcium chloride (adding potassic acetate). Gather the oxalate of calcium, wash, dry, and ignite to carbonate (adding ammonium carbonate and igniting slightly again, if necessary), Ca CO, 2CH ̧O ;; 1 : 0.64.

192. ETHYLIC ALCOHOL. CHO. Characterized by its physical and sensible properties (a); by the extent of its reducing power (b); by its formation of iodoform (c); of various compound ethers (d), and of acetic acid (e).—Separated by fractional distillation, solubility in water, and insolubility in fixed oils. Separated from methylic alcohol as an oxalic ether (191, g), from amylic alcohol by solution in water or by fractional distillation.-Determined by the specific gravity or by the boiling point of its mixtures with water.

a. A transparent, limpid liquid, of spec. grav. 0.794, freezing at -95° C. and boiling at 78° C. (173° F.), of an agreeable and pungent odor and a sharp and burning taste. It is miscible with water, ether, chloroform, benzole, petroleum naphtha, volatile oils and castor oil, and dissolves resins and camphors.

b. Alcohol-as a hot liquid or as vapor-slowly reduces chromic acid, or a mixture of potassic bichromate and sulphuric acid—the alcohol being first oxidized to acetic acid. (This is in common with aldehyde, acetic acid, formic acid, and many volatile organic bodies.) Permanganate of potassium is but slowly reduced by ethylic alcohol-so that the red tinge of a slight addition of a T solution is scarcely at all affected for several minutes. (Methylic alcohol, Formic acid, Aldehyde, and many other volatile organic bodies, more readily reduce the permanganate.)

c. The production of iodoform from alcohol is a result (in part) of the reducing power of the latter upon alkaline iodate:

6KHO+61=5KI+KIO,+3H,O

KIO,+C2H ̧0+21=CHI,+KCHO2+2H,0

Take 3 to 5 c.c. of the distillate to be tested, 5 to 6 drops of a 10 per cent. potassa solution; warm to 100° or 120° C. (212° to 248° F.), and add-of a solution of potassic iodide in five parts of water, saturated with iodine-until the liquid is brownishyellow. If, on agitation, the color does not disappear, add one or two drops of the potassa solution. If alcohol is present, the iodoform appears, sooner or later, in yellow scaly particles. With a power of 200 to 400 diameters, these are seen as hexagonal stars and rosettes. Iodoform is formed also by Aceton, Aldehyde, Acetic ether, Butyric alcohol, Amylene. Not formed by Ether, Amylic Alcohol, Chloroform, Chloral, Chloral Hydrate, and, according to LIEBEN, not formed by Methylic alcohol.

d. See under Acetic acid, 40, b, and Butyric acid, 41, b. (One c.c. of the distillate to be tested is treated with 0.3 to 0.5 gram of dry potassic acetate and 2 or 3 c.c. of sulphuric acid.)

e. Acetic acid is formed from alcoho! by digestion with a mixture of bichromate of potassium and dilute sulphuric acid, or of permanganate of potassium and dilute sulphuric acid. See 40.

193. ALDEHYDE. C ̧ÃO. Acetic Aldehyde.—A trans

parent and colorless liquid, of spec. grav. 0.800 at 0° C., distilling at about 21° C. (70° F.), neutral in reaction, of a pungent and suffocating odor, slightly resembling that of apples. The vapor irritates the eyes.—It is miscible in all proportions with water, alcohol, and ether, but not with aqueous chloride of calcium (separation from Alcohol). It dissolves sulphur, phosphorus, and iodine. It promptly reduces ammonio nitrate of silver, forming a specular coating on the glass (distinction from Acetic acid, Alcohol, Ether). It burns readily, with a blue flame. It is blackened by sulphuric acid.-Potassa solution, warmed with aldehyde, colors it brown, with deposition of " aldehyde resin" and formation of acetate and formate (a characteristic test). Ammonia (gas) with aldehyde forms aldehyldate of ammonium, a compound of an ammoniacal, terebinthinate odor, crystallizing (from ether or alcoholic ether) in transparent acute rhombohedrons, melting between 70° and 80° C., and distilling at 100° C. It dissolves in water, sparingly in alcohol and ether. With other bases aldehyde acts as a monobasic acid, exchanging one atom of its hydrogen.

194. SULPHETHYLATES. HC,H,SO. Ethyl-sulphates. -Sulphethylic acid is a limpid, oily, acid liquid, of spec. grav. 1.315, decomposed by heat, evolving ether at 130° to 140° C. (266° to 284° F.)-It is soluble in water and alcohol, not in ether.—Its metallic salts are all soluble in water, and are mostly soluble in aqueous but not in absolute alcohol, the ammonium salt only is soluble in ether. The sulphethylates are gradually decomposed in boiling water. Barium sulphethylate crystallizes in permanent monoclinic prisms, with 2H2O which is expelled in a vacuum, the anhydrous salt bearing 100° C. without change. It dissolves in about one part of water, and in a larger quantity of aqueous alcohol. The sodium salt crystallizes in slightly efflorescent hexagonal plates, with H2O, soluble in less than one part of water, melting at 86° C. When anhydrous, it bears 100° C. without change.

195. ETHER. (C,H,),O. Recognized by its sensible and physical properties (a). Separated by distillation, or by solution (b).

a. Spec. grav., at 15° C., 0.713; at 17.5° C., 0.7185. Boiling point, 35° C. (95° F.) Ether of spec. grav. 0.728, and boiling at blood heat, has from 5 to 6 per cent. of about 90 per cent. alcohol; that of spec. grav. 0.750 has about 25 per cent. of 88 per cent. alcohol.-At 17.5° C. (63.5° F.), one part of ether dissolves in 12 parts of water, and 35 parts of ether dissolve one part of water. Alcoholic ether is more soluble in

water:

"Ether" of sp. gr. 0.719 to 0.721 dissolves in 12.0 parts water. 66 0.724" 0.726 66 ❝ 10.0 66

66

66

66

Salts not soluble in ether (as dry potassic carbonate) separate it from water almost wholly. Ether is miscible in all proportions with alcohol, chloroform, benzole, petroleum naphtha, fixed and volatile oils, and dissolves resins. sulphur, phosphorus, iodine, and ferric, mercuric, and auric chlorides. Tannic acid does not dissolve or deliquesce in absolute ether, but deliquesces ir. the "stronger ether" of spec grav. 0.728. Ether is less oluble in glycerin than in water. It mixes with concentrated sulphuric acid, the liquid turning brown when warmed.-In the air, ether very slowly oxidizes to acetic acid. Its combustibility renders it necessary to use strict precautions in the manipulation of its vapor.

3. Ether is approximately separated from alcohol by means of glycerin (or water). A test-tube of over 20 c.c. capacity is graduated from the point of 10 c.c. contents (marked 0) to the pain 20 cc. contents (marked 10). Ten c.c. of glycerin or

water is taken in the tube, then 10 c.c. of the ether is added, the contents shaken together, the ether allowed to separate, and the increase in the lower layer is read off.

196. NITROUS ETHER. CH,NO,. Nitrite of ethyl.— Characterized by its sensible and physical properties (a) and by reactions of nitrites.—Estimated, in its alcoholic mixtures, by their boiling point (b), and by volumetric trial with permanganate (c).

a. Nitrite of ethyl is a yellowish liquid, of spec. grav. 0.947, boiling at 16.6° (62° F.), and of an agreeable odor of apples. It is soluble in 48 parts of water, in all proportions of alcohol, and freely soluble in dilute alcohol. It gradually decomposes; more quickly in contact with water.

b. "Spirit of nitrous ether," of 5 per cent. nitrite of ethyl, boils at 63° C. (145° F.): the test-tube containing it being immersed in water of that temperature, and a few fragments of broken glass added.

Quantitative.- -C. 10 grams of the spirit of nitrous ether are macerated, with 1.2 to 1.5 grams of fused potassa, in a stoppered flask, for 12 hours, occasionally agitating. Then pour the mixture into a beaker, dilute with an equal bulk of water, and leave at a warm temperature till the odor of alcohol disappears. Acidulate slightly with sulphuric acid, and add, from a burette, a solution of potassium permanganate of known strength, until the color ceases to be discharged. The number of grams of permanganate expended, multiplied by 1.18, equals the number of grams of ethyl nitrite in the 10 grams of material taken.

197. CHLOROFORM. CHCI,. Identified by its sensible and physical properties (a); its liberation of chlorine when decomposed (b), and its production of isonitril (c). It acts as a reducing agent (d). It is separated by washing with concentrated sulphuric acid and with water, and rectification from alkaline carbonate, lime, calcium chloride, animal charcoal (e). It may