[ 346 ] 
Alum 1,033 Nitre purified 1,095 
Genuine Glau. fait 1,052 Rochelle fait 1,114 
Vitriolated tart. 1,054 Blue vitriol 1*150 
Common fait 1,198 Green vitriol 1,157 
Arfen. nitre 1,184 Sal gemmas 1,170 
Glau. fait Lyming. 1,232 Epfom fait Lym. 1,218 
Sal ammon. 1,072 White vitriol 1,386 
Vol. fait of fal. am. 1,077 Pearl afh 1 ,53 4 
Cryftals of kelp 1,087 
By making other tables fimilar to the preceding,, 
when the thermometer ftands at 62°, 82°, 102°, &c. 
or when the heat increafes or decreafes in any known 
ratio; it is extremely probable that the law, accord- 
ing to which the diffolving power of water varies - 
with the variation of its heat, might be inveftigated- 
I have fome reafons for thinking that though it in- 
creafes with the increafe of heat, yet it doth not 
increafe in the direct fimple ratio of the heat ; but 
what the law is, or whether all falts follow the fame 
law, I cannot, from any experiments I have already 
made, determine ; and 1 have no leifure at prefent to> 
profecute the enquiry. The conclufion will be un- 
avoidably liable to a fmall inaccuracy for whether 
the fpecific gravities be inveftigated by weighing the 
feveral fluids in a given veflel filled to a given mark, 
or by weighing a given folid in. each of them, we 
fhall not thence obtain the weights of equal bulks, 
fince the containing veflel or the folid, from the 
difference of the heats, have a different capacity or a 
different bulk. However, it is not apprehended that 
this circumftance would fenfibly affedt the conclu- 
fion, efpecially as it is fubjedt to calculation and 
might 
