RELATIVE ATTRACTIONS, ETC. 353 
give us no information on the subject ; but, from 
some of them, we learn that experiments have 
been made on the extent to which the acid 
becomes diluted by exposure to the atmosphere ; 
these experiments, however, being so limited in 
their nature as to fall far short of eliciting that 
information which it has seemed to me desirable 
for us to possess. In Dr. Ure’s Dictionary we 
are told that, if suffered to remain in an open 
vessel, it imbibes one-third of its weight in 24 
hours, and more than six times its weight in a 
twelve month. And in Dr. Thomson’s System 
of Chemistry we are told that Newman found, 
that, when exposed to the atmosphere, it attracted 
6.25 times its own weight; and that Mr. Gould 
found that 180 grains of it, when exposed to the 
atmosphere, attracted 68 grains of water the first 
day, 58 the second, 39 the third, 23 the fourth, 
18 the fifth, and at last only 5, 4, 3, &c.; the 
28th day the augmentation was only half a grain. 
We are not informed in what state of dryness 
the atmosphere was during these exposures, nor 
have we anything beyond evidence that sulphuric 
acid has a strong attraction for water. 
In the course of some experiments which I 
was some time ago conducting to ascertain the 
re 
