A manual of pharmacy / by William Thomas Brande.

Date:
1833
Catalogue details

Licence: Public Domain Mark

Credit: A manual of pharmacy / by William Thomas Brande. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    I.iquid Acetic Acid ' GO. Acetate of Soda (drj') 83 c= 137 crystallised. Sulphate of Soda (dry) 72. Acetic Acid -J- Water (dry) 51 9 Soda ^-Sulphuric Acid 32 (dry) 40 Liquid Sulphuric Acid 49 It is thus, then, by saturating any of the dilute acetic acids by a metallic oxide, and decomposing the dry acetate so ob- tained by sulphuric acid, that vve procure pure and concen- trated acetic acid. In this state it used to be called radical vinegar. It is a transparent, colourless, volatile, and acrid liquid, which crystallises at about 40°. and has a specific gravity of 1.060. Its vapour is inflammable. When duly diluted with water, it closely resembles distilled vinegar. The real strength of this acetic acid cannot be judged of, like that of many other acids, by a reference to its specific gravity ; for samples of the same density are continually found to vary extremely in the proportion of real acid which they contain, owing partly to the presence of what has been termed pyro- acetic or pyroxylie spirit^, a. substance into which the acetic acid appears convertible, and which is formed at its original distillation from the wood, as well as in some of the after- processes of purification. Besides which, there is not only not that marked difference between the specific gravity of acetic acid of different strengths that enables us to resort to that criterion, without instruments of extreme delicacy, but a ’ This is the composition of what is sometimes known under the name of glacial acetic acid, in consequence of the facility with which it crystallises at tem- peratures below 40®. ^ Fyroacetic spirit has a penetrating ethereal odour, an acrid taste, and a spe- cific gravity, after having been distilled off'muriate of lime, of 0*828. It burns with a blue flame, leaving no residue, but producing a peculiar smell. It is inso- luble in water, but soluble in alcohol. When distilled with its volume of sul- phuric acid, it is not altered; hence evidently distinct from alcohol, for which, however, it may be used as a substitute in lamps. According to Messrs. Macaire and Marcet, (Biblioth. Univers., October, 1823,) it consists of Carbon 44*53 Oxygen 46*31 Hydrogen 9*16 100 It is highly stimulating and diaphoretic as a medicine.