Hygrometry. i r 
well as the porous mineral ones, received water merely by the 
faculty of capillary pores , I ufed fometimes the expreffion hy~ 
grofcopic affinity , in treating of the hygofcropic equilibrium ; but 
before that work was come out of the prefs, having converfed 
on that objedt with Dr. Blagden, and found him inclined to 
that opinion, I had time and opportunity to exp refs it, in 
§ 276, as follows : “ There are reafons to doubt, whether fome 
€t of the fubftances, which fihare amongft them the water dif- 
u feminated in a fpace, do not fuck it, by a faculty fimilar to 
cc that of capillary tubes , without any chymical affinity with 
“ water” That opinion will be now confirmed by the fol- 
lowing experiments. 
16. 1 ft. Exp. Sugar has an affinity with water, and no fen- 
Able one with alcohol : however, a lump of fugar will imbibe 
this laft liquid as readily as the firft. Confequently, water h 
not imbibed by fugar in confequence of their affinity ; fince 
alcohol is alfo imbibed : they both afcend in fugar , by the faculty 
of its capillary pores , as they do in fandfone or in fpunge . 
But when water has thus entered fugar , it diffolves it ; which 
then is a chymical effedt ; whereas alcohol evaporates, and leaves 
the fugar lenlibly as it was before. 
1 7. 2d. Exp. If water penetrated hygrofcopic fubftances of 
the vegetable and animal kinds, by an affinity with them, it 
would not be natural to expedt, that other liquids , which do 
not (hew an affinity with the fame fubftances as water , fhould 
penetrate the above-mentioned fubftances. Being led by that 
confideration, I made two hygrofcopes of different elaftic animal 
fubftances ; and after having marked the point where they 
flood in water, I immerfed them fucceflively in alcohol and in 
ether ; by which liquids they were expanded nearly as much as 
by water , and they contracted as much in coming out of them. 
C 2 In 
