As acid of the above strength is rarely required, and as the distillation is more easily conducted when the ingredients are less concentrated, a little water may be conveniently added either before or towards the end of the distillation. Hence the following proportions have been recommended:—— 2. (Völckel.) Acetate of lime (as last), 100 parts; hydrochloric acid (sp. gr. 1·16), 90 to 95 parts; water, 25 parts; mix, and proceed as before. Prod. 96 to 98 parts of an excellent acid, well adapted to trading purposes, having a sp. gr. about 1·050, and containing nearly 40% of hydrated acetic acid. It has been correctly remarked, that the acetic acid produced with hydrochloric acid is always of better quality than that produced with sulphuric acid; being not only less coloured, but also entirely free from sulphurous acid. The distillation uniformly proceeds with ease and regularity, and the whole of the acetic acid passes over between 212° and 248° Fahr.; by which the danger of contamination with other products, resulting from a high degree of heat, is obviated. 3. 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. [Illustration: _A_, Furnace. _B B B B_, Glass receivers. _C_, Stoneware retort. _D_, Bottle containing vinegar. _E E E E_, Basins containing water. _F F F F_, Supports for basins. _G_, Welter safety-tube. _H_, Supply-pipe of cold water. _I I I I_, Cocks to supply water to the basins. _J_, Water main. _L_, Adapter connecting retort and globes.] II. _From_ the _Acetates_ by _dry distillation_ with a _sulphate_:—— _a._ From ACETATE OF LEAD:—— 1. Acetate of lead (dried), 5 parts; and sulphate of iron (gently calcined), 2 parts; are separately powdered; and after thorough mixture, carefully distilled, by the heat of a sand bath, into a well-cooled receiver. An economical process for a strong acid, under certain circumstances; but one now seldom adopted. 2. (Bardollier’s Strong Acetous acid.) Dried acetate of lead, 10 oz.; calcined green vitriol, 12 oz.; as the last. _b._ From the ACETATES OF COPPER:——By substituting acetate or diacetate of copper, in equiv. proportions, or better with excess of the sulphate. Seldom used. _c._ From ACETATE OF POTASH, as the last. III. From the _Acetates per se_:——