( 1 ° ) 
half. It is difficult to determine exadly what Quan- 
tity of either was loft by. this Calcination, but it will 
eaftly be granted, that there was loft a, far larger Quan- 
tity of the Blood, than of the Salt of Tartar^ and that is 
obvious from an Experiment, by whieht when the Salt 
of Tartar was calcined by itfelf, with the fame Degree 
of Heat, it loft lefs than an i Part, whereas, when the 
dry’d Blood was calcined by itfelf, it loft more than |. 
The Blood, in Calcination with the Salt of Tartar, 
communicates its tinging Quality to the Salt, or 
that Quality is extracted from it by the Salt, and paftes 
with it in its Diffolution in the boiling Water* 
To prove this, fome dry’d Blood was calcin’d by it 
felf, and a ftrong Deco&ion was made of it in Water, 
and afterwards filtred : this, when mix’d with the for- 
mer Solutions, produced little or no Alteration but on 
the Addition of the Spirit us Suits , changed to an Am- 
ber Colour, without any Precipitation. 
When this Liquor was mix’d with the 01 . Tdrtari , 
and poured to the former; Solutions, it caus’d a Precipi- 
tation, but no Colour, anffith zSpiritus Salts , as in the 
other Experiment, made the Liquor clear again, but 
left this alfo of an Amber Colour. 
The Change of Colour is not effeded in any of the 
Materials, except in that of the Solution of Vitriol, fo 
that the Alum fee ms only to be of ufe in fixing the 
Colour, as it is often us’d by the "Dyers for that Pur- 
pofe, and the Spiritus Salts gives it a deeper Dye. For 
if the Lixivium with Blood be poured to the Solution 
of Alum alone, there will fall a Sediment a little on 
the Purple, to which if you add the Spiritus Salts , it 
changes the Colour, and the Sediment is of a Brown. 
So, much the fame changes will be produced, if you 
pour the Spiritus Salts to the Lixivium , but not the 
leaft Appearance of a Blue, whereas, as is beforemention’d, 
when 
