

HYDROMETER. 



M. Baume, in his " Elemens de Phar- 

 macia," has given a table of the degrees 

 of his hydrometer for spirits, indicated by 

 different mixtures of alcohol and pure 

 water, where he says, the spirit made use 

 of gave 37 degrees at the freezing point 

 of water ; and in a column of the table 

 he states the bulk of this spirit, compared 

 with that of an equal weight of water, as 

 35| to 30. The last proportion answers 

 to a specific gravity of 0.842, very nearly. 

 A mixture of two parts, by weight, of this 

 spirit, with thirty of pure water, gave 

 twelve degrees of the hydrometer at the 

 freezing point. This mixture, therefore, 

 contained 6 parts of Blagden's standard 

 to 100 water ; and by Gilpin's excellent 

 tables, its specific gravity must have been 

 0.9915. By the same tables these specific 

 gravities of 0.842 and 0.9915 would, at 

 10 Reaumur, or 55 Fahrenheit, have 

 fallen to 0.832 and 0.9905. Here then are 

 two specific gravities of spirit correspond- 

 ing with the degrees 12 and 37, whence 

 the following table is constructed. 



BAUME'S HYDROMETER FOR SPIRITS. 



Temperature 55 Fahrenheit, or 10 

 Reaumur. 



With regard to the hydrometer for 

 salts, the learned author of the first part 

 of the *' Encyclopedic, Guyton de Mor- 

 veau," who by no means considers this 

 an accurate instrument, affirms, that the 

 sixty-sixth degree corresponds nearly 

 with a specific gravity of 1.848; and as 

 this number lies near the extreme of the 

 scale, I shall use it to deduce the rest. 



BAUME'S HYDROMETER FOR SALTS. 



Temperature 55 Fahrenheit, or 10 

 Reaumur. 



It may not be amiss to add, however, 

 that in the Philosophical Magazine, Mr. 

 Bingley, the assay-master of the Mint,*has 

 given the following numbers as the speci- 

 fic gravity of nitric acid, found to answer 

 to the degrees of an areometer of Baum6 

 by actual trial ; temperature about 60 

 Fahrenheit. But his appears to have been 

 a difFerent instrument, as it was graduat- 

 ed only from to 50. 



One of the principal uses of the hydro- 

 meter in common life being to determine 

 the specific gravity of vinous spirits on 

 the mixtures of alcohol, which consist of 

 water, an article of no value in a commer- 

 cial light, and alcohol, which is of consi- 

 derable price, it becomes of importance 

 to determine how much of each may be 

 contained in any mixture. The following 

 tables, extracted from the large table of 

 Gilpin in the " Philosophical Transac- 

 tions," may be considered as of the first 

 authority. They were made with mix- 

 tures of water and alcohol, of 0.825 at 60. 

 The alcohol was obtained from malt. 



