Acetate

“ When there is no more frothing up, and the mass flows like oil, the operation is finished. It is now allowed to cool in a body, or it may be ladled out into moulds, which is preferable.
When the acetate is dissolved in water, the charcoaly matter proceeding from the decomposition of the tar must be separated by filtration, or by boiling up the liquor to the specific gravity 1·114, when the carbonaceous matter falls to the bottom. On evaporating the clear liquor, we obtain an acetate perfectly fine, which yields beautiful crystals on cooling. ”

“ A subacetate of lead is formed by digesting a cold solution of uncrystallized acetate, over litharge, with frequent agitation. It is said that 65 pounds of purified pyrolignous acid, of specific gravity 1·056, require, for making a neutral acetate, 58 pounds of litharge ”

“ The acetate of soda crystallised and ground is put into a copper, and the necessary quantity of sulphuric acid of 1·842 (about 35 per cent. of the salt) to decompose almost, but not all, the acetate, is poured on. The materials are left to act on each other; by degrees the acetic acid quits its combination, and swims upon the surface; the greater part of the resulting sulphate of soda falls in a pulverulent form, or in small granular crystals, to the bottom. Another portion remains dissolved in the liquid, which has a specific gravity of 1·08. ”

“ If, whilst heated, it emits fumes, it is suffering decomposition. The same applies to the other commercial acetates. Crystallised acetate of soda loses about 2⁄5ths of its weight by thorough drying.
When acetate of soda and sulphuric acid are the ingredients employed in the production of acetic acid, sulphate of soda is formed, which, in the large way, the chemist returns to the manufacturer of acetate of soda (i. e. to the pyroligneous acid maker) , who employs it in the decomposition of fresh acetate or pyrolignite of lime. ”

“ When a solution of soap and sub-acetate of lead are added together, the potass of the former combines with the acetic acid of the latter, and the fat and oxyd of lead are disengaged; the one rising to the surface, while the other is precipitated; and yet notwithstanding this complete decomposition, some surgeons are in the habit of using an application which consists of a drachm of the Liquor Plumbi Sub-Acetatis, and two ounces of the Linimentum Saponis! We cannot have any hesitation in deciding upon the inefficacy of such a mixture. ”

“ Acetic acid, familiar to us in a diluted and flavored form as vinegar, is when concentrated of great value in industry, especially as a solvent. I have already referred to its use in combination with cellulose as a "dope" for varnishing airplane canvas or making non-inflammable film for motion pictures. Its combination [Pg 243] with lime, calcium acetate, when heated gives acetone, which, as may be seen from its formula (C3H6O) is closely related to the other compounds we have been considering, but it is neither an alcohol nor an acid. It is extensively employed as a solvent. ”

“ It is the RADICAL VINEGAR of the alchemists, and it is that which is preferred by the perfumers. Well-dried acetate of lead, or of iron, as well as several other acetates, may be substituted for acetate of copper in the above process; but are less economical and convenient. In all cases, great care must be taken to avoid over-firing, as thereby the quantity obtained is lessened, and the quality injured. The residuum of the distillation is pyrophoric and frequently inflames spontaneously, on exposure to the air. ”

“ The solution of acetate of ammonia may be recovered from [232] the white lead, and be repeatedly used, for the conversion of further quantities of oxide of lead into hydrate and acetate of lead, which hydrate and acetate are converted into carbonate of lead by the injection of carbonic acid. Theoretically, a given weight of acetate of ammonia in solution, used in conjunction with carbonic acid, should be capable of converting an unlimited quantity of oxide of lead into carbonate of lead ”

“ Its aqueous solution gives a white precipitate with both normal and basic lead acetate, which when heated, acquires first a rose, and then a chocolate colour; with ferric chloride a green liquid is produced, which changes after a time to red and becomes black on addition of sodium acetate. It forms white precipitates with gelatin, albumen, and alkaloids. By dry distillation it yields catechol. By fusion with potash or the action of sulphuric acid, phloroglucol and protocatechuic acid, while nitric acid converts it into oxalic and picric acids. ”

“ When we attempt to ascertain the relative preserving power of the neutral salts, it will appear that those whose acid forms with the lead a soluble salt of lead are the least energetic; while those whose acid forms an insoluble salt of lead are most energetic. The protecting powers of acetate of soda, nitrate of potass, muriate of soda, sulphate of lime, arseniate of soda, and phosphate of soda, are inversely as the solubility of the acetate, nitrate, muriate, sulphate, arseniate, and phosphate of lead. ”

“ The Acetic Acid and Ammonia become neutralized by combination with each other, affording a compound of new virtues. Sulphate of Zinc, and Acetate of Lead, when mixed together in solution, decompose each other, and the Acetate of Zinc which is formed, affords a more valuable remedy than either of the former salts, as an application in ophthalmia. The “Mistura Ferri Composita” of our Pharmacopœia offers another example of the same chemical resource. ”

“ Acetic amyl ether or amyl acetate, C5H11O.C2H3O, is prepared by mixing 1 part of amyl alcohol with 1 part of concentrated sulphuric acid, and distilling the mixture with 2 parts of potassium acetate. The distillate is washed with water, to which some carbonate of soda has been added, and then rectified over magnesia. It forms a colorless liquid of an agreeable fruity odor. ”

“ An Acetic acid sufficiently strong and pure for many ordinary purposes may be obtained without distillation, by pouring strong sulphuric acid, 60 parts, diluted with water, 5 parts, on well-dried acetate of lime, 100 parts; digesting, with occasional agitation in a close vessel, decanting the clear liquid, and straining the remainder. ”

“ The digestor is closed, and the temperature rises. As the temperature rises, and approaches 212° F., and as the pressure, due more especially to the tension of vapour of ammonia set free during the reaction with the litharge, increases, so is the rapidity of the conversion of the oxide into basic acetate increased, and more and more of this basic acetate becomes dissolved, whilst at or about 212° F. it is entirely in a state of solution. The degree of heat, or the prolongation of the heat, depend of course upon the state of dilution of the acetate of ammonium used. ”

“ It is at once seen that I have got the requisite quantity of acetate formed. I next dissolve the requisite quantity of arsenious anhydride in an amount of carbonate of soda rather less than is sufficient to neutralize the acid in the remaining cupric sulphate, and I then bring the solution to or near the boiling-point by introducing steam into it; the arsenic is dissolved not in the same vessel as the copper salt, but in a separate one. ”

“ L.) “100 measures of a solution of 10 gr. in 1⁄2 fl. oz. of water, and 5 minims of acetic acid, heated to 212° and decomposed by a very slight excess of ammonia, yield by agitation a precipitate which, in 24 hours, occupies 151⁄2 measures of the liquid.” (Ph. E.)
Obs. The acetate of morphia of commerce is usually in the form of a whitish powder, and is prepared by the mere evaporation of the solution to dryness by a gentle heat. ”

“ It is a monobasic acid, forming one normal and two acid potassium salts, and basic salts with iron, aluminium, lead and copper. Ferrous and ferric acetates are used as mordants; normal lead acetate is known in commerce as sugar of lead (q.v.) ; basic copper acetates are known as verdigris (q.v.) .
Pharmacology and Therapeutics.—-Glacial acetic acid is occasionally used as a caustic for corns. The dilute acid, or vinegar, may be used to bathe the skin in fever, acting as a pleasant refrigerant. Acetic acid has no valuable properties for internal administration. ”

“ Cellulose Acetate (Cross) .—If cellulose is heated with acetic anhydride at 180° C., viscous solutions of the acetates are obtained. The process yielding a definite acetate of commercial value is based upon the following reaction:—100 parts of cellulose prepared from the sulpho-carbonate are mixed with 120 parts of zinc acetate, heated and dried at 105° C. Acetic anhydride is added in small quantity, and 100 parts of acetyl chloride. At a temperature of 50° C. the mixture becomes liquid, and cellulose acetate is subsequently obtained as a white powder. ”

“ White lead is prepared according to very different methods, the principle of which consists in subjecting a solution of tribasic lead acetate to the action of carbonic acid, by which the basic carbonate is produced and the neutral acetate formed, the latter being then reconverted into the basic acetate, which again serves to produce white lead and so on. ”

“ We must carefully avoid raising the temperature so high as to decompose the acetate, and be sure that the heat is equally distributed; for if any point of the mass enters into decomposition, it is propagated with such rapidity, as to be excessively difficult to stop its progress in destroying the whole. The heat should never be so great as to disengage any smoke, even when the whole acetate is liquefied. ”

“ Almost insoluble in water; insoluble in alcohol. Lead oxide is only valuable for its preparations.
PREPARATIONS PLUMBI ACETAS—LEAD ACETATE—SUGAR OF LEAD
Derivation.—Heat lead oxide in acetic acid and water. Lead acetate crystallizes on cooling.
Properties.—Colorless, shining, transparent; monoclinic prisms or plates, or heavy, white crystalline masses, or granular crystals, having a faintly acetous odor and a sweetish, astringent, afterwards metallic taste. Efflorescent and absorbing carbon dioxide on exposure to the air. Soluble in two parts of water and in thirty parts of alcohol. ”

“ After about 12 hours, by the simultaneous action of the vapours of acetic acid and the oxygen of the air, lead acetate is formed. Carbonic acid is now led into the chambers. The carbonic acid is obtained by burning charcoal in a cylindrical furnace; it is cooled by being passed through a long iron tube before it enters the chamber. For 12,500 kilogrammes of lead there are required every day about 482 litres of dilute acetic acid, obtained by mixing strong acetic acid with water until the mixture contains 4·5 per cent. ”

“ Quite recently numerous experiments have been carried out with the object of finding methods for employing the cellulose esters of organic acids in the preparation of fabrics. The acetate, which is generally used, gives solutions from which fibres can be obtained which are comparable to natural silk in strength, and which have the further advantage of being non-inflammable, and far less readily affected by water than artificial fabrics obtained by the above methods. It is prepared by treating cellulose with dilute acid, by which the so-called ‘hydrocellulose’ is obtained ”

“ The product is 38 to 381⁄2 parts of crystallised sugar of lead. It is found to be advantageous to preserve a very slight excess of acid during the boiling and crystallisation, to prevent the formation of any basic acetate the presence of which impedes the formation of regular crystals.
From litharge, 112 lbs.; acetic acid (sp. gr. 1·057) , 128 lbs. Prop. 180 to 184 lbs. ”

“ Acetate of Alumina is prepared in large quantities for the calico printers, by decomposing alum with acetate of lead, or more economically with aqueous acetate of lime, having a specific gravity of about 1.050, a gallon of which, equivalent to nearly half a pound avoirdupoise of dry acetic acid, is employed for every 21⁄2 lbs. of alum. A sulphate of lime is formed by complex affinity which precipitates, and an acetate of alumina floats.—Ure. ”

“ Of the astringents, acetate of lead, sulphate of zinc, tannic acid, nitrate of silver are the most valuable. Many others—perchloride of iron, chlorate of potassium, hydrastis canadensis, salicylic acid and its preparations, carbolic acid, etc.—have been commended. In all cases the strength of [p. 347] the injection should be short of causing the patient much pain. It is always best to begin with a mild solution and gradually feel the way up to stronger ones. Of all the astringents, I prefer nitrate of silver, which I use in strengths varying from one grain to twenty to the fluidounce. ”

“ Aluminium acetate in the pure state is also rarely employed, the crude commercial “ red liquor" being found in practice to yield the best results, both as regards colour and ease of working. The “ red liquors " vary considerably in composition, some being normal acetates, others basic acetates, some normal sulphate-acetates, others basic sulphate-acetates, but their mode of application is always the same, that is, they are thickened, printed, aged and dyed in alizarine If they are too basic they decompose on boiling, or on dilution, and become utterly useless ”

“ White, odorless or nearly odorless powder or crystalline masses with a warming, saline taste. Freely soluble in water (1:0.5) and in alcohol (1:2.9) .
Action and Uses: Systemic alkali and diuretic, practically equivalent to sodium acetate. It can easily be administered in water and milk, so that there appears to be little excuse for the alcoholic elixirs.
Dosage: 1 Gm. or 15 grains (U.S.P.) .
Elixir Potassii Acetatis (Elix. Pot. Acet.) , Elixir of Potassium Acetate, N.F.—Potassium acetate (8.5%) , and aromatic elixir. Absolute alcohol content about 20 per cent. ”