AMERICAN JOURNAL OF PHARMACY. 
JANUARY, 1 852. 
ON THE CORRESPONDENCE OF THE DEGREES OF BEAUME'S 
HYDROMETERS WITH SPECrFIC GRAVITY. 
By Henry Pemberton. 
Read at the Pharmaceutical Meeting of the College held September 1st, 1851. 
There is no instrument in such general use, and upon whose 
indications so much depends, that is liable to the variations and 
gross errors that affect so seriously Beaume's Hydrometers. It is 
well known that two hydrometers seldom mark like degrees, when 
plunged into the same liquid, and often vary so greatly that they 
become utterly useless. This faulty construction is generally 
attributed to the maker of them, and to some extent with justice, 
for many are so carelessly made that they will not float upright, 
or the stem evidently so unequal in diameter as to render it use- 
less to seek for further cause. But it is not so generally known 
that the value of the degrees of the scale is equally uncertain, and 
though the hydrometer may be carefully made, there is no standard 
scale by which to obtain the value of any given degree. It is 
true that when Beaume first invented his scale, he had relative 
values for each degree, but as the system of graduation for up- 
wards of thirty years has been different from that upon which he 
constructed his instrument, they would be useless for comparison, 
if obtainable. This is to be regretted, more especially in the case 
of hydrometers for liquids denser than water, these being most 
