3i8 appendix. 
87. There are Effervefcences which ac- 
quire neither Heat nor Cold, as Spirit of 
Sea Salt with Lead in vacuo. 
‘^88. There are alfo great Effervefcences 
which produce Cold^ as Oil of Vitriol and 
‘‘ Sal Ammoniac., as in Number 76^ 77; it 
is the fame alfo with Oil of Vitriol and 
volatile Salt of Urine. 
8p. Whence our Author would infer, that 
thefe Degrees of Cold are acquired by the 
flying away of the Fire with the rifing 
Fumes 5 and that the Heat of thefe Effer- 
vefcences is not owing to the inteftine Motion 
of the Parts, but to a real inherent elemental 
Fire, on the flying away of which Cold is 
produced. 
5>o. But when we confider, how vafll^ 
greac the attraftive and repulfive Force of 
many of the Particles of Matter are, neat 
the Point of Contaft, it feems not impro- 
bable that the acquired Heat of cflPervefcent 
Mixtures may be owing to the inteftine Mo- 
rion arifing from thofe contranitent and much 
agitating Powers ; which as they are varied 
by infinitely different Combinations,’ fo their 
Effedls muft needs be proportionably varied^ 
fome Copibinacions tending to promote and 
greatly 
