[ 300 ] 
A Portion of this Stone, in a ftrong open fire, 
loft in Calcination juft half its Weight 5 becomings 
as the former, a white infipid Earth 5 which, being 
infufed in boiling Water, made no Alteration in its 
Colour, Tafte, nor Smell. 
Three Ounces of this Stone diftili'd, produc'd 
Gr. 24. f more than an Ounce and a Quarter of the like 
alkaline Spirit as the former yielded, and left a black 
Coal, weighing Gr. 167^ above an Ounce and half. 
From this chemical Analyfis it appears, that thefe 
Stones are compounded chiefly of Earth, a large 
.Quantity of volatile alkaline Salt and Water, fome 
Oil, and a fmall Quantity of Air. 
From hence it likewife appears, that the compo- 
nent Principles of thefe Stones bear a nearer Refem- 
blance to thofe of Hartfhorn than that of the Calcu- 
lus humanus : For, according to Dr. Haless Account, 
in his Vegetable Statics , Experiment N°. 51- 
241 Grains of Deer's Horn being diftillxi left a Calx 
weighing Gr. 1:285 viz,, above half its Weighty 
which {hews that Horn contains much about the 
fame Quantity of Earth as thefe Stones do : Whereas 
the Calculus humanus, when diftili'd., affords but a 
.fmall Quantity of Earth, Spirit, or Oil 5 the greateft 
Part of it being converted into Air. 
Half an Ounce of the Stone ( Fig * 7. Tab. III.) 
being powder'd and infufed in four Ounces of boil- 
ing Water., made it fmcll ftrongly of Horfe-Dung, 
and gave it a difagreeable Tafte, while it was hot 5 
but. 
