On the Animal Calculus. 243 
VloYtnce Flasks to a large Orifice, which being 
firfl: weighed were filled with equal Qiianticies 
of Water which was alfo w^eighed, thefe be- 
ing fet on a Sand Furnace were there evapo- 
rated with a gradual equal Heat. The Se- 
diment of the Rain Water was of a darker 
brown Colour than that of Comb Water ; this . 
lafl: in a few Days melted fo as to ftand in 
fmall Drops, whence \is likely there may be 
a' very fmall Degree of Salt in it, and that 
probably of a nitrous kind. From a like Qiian- 
tity of Scarborough Spaw Water I procured 
forty eight Grains of Sediment, i. e. in the 
Proportion of one to a hundred and eighty 
five ; it was near as white as double refined 
Loaf Sugar, in (landing fome Days it melted 
and had a very naufeous bitter Tafte, as that 
of Ebjham and the like purging Waters have. 
The Sediment from a like Quantity of Brijiol 
hot Well Water was four Grains, L e. in the 
Prop^ortion of i to 22^2; it (hoc into Stria 
like the Scarborough Spaw Water, and w^as 
white like it j in (landing fome Days it melt- 
ed, but had no difagreeable Taile. On the 
Evaporation of half a Pound of Havering 
Well purging Water there remained 24 + J 
Grains of Sediment, i, e, as one to a hundred 
R ^ and 
