( 39') 
Salt, by mixing it with Oil of Vitriol. The Mix- 
ture of Borax giv with Oil of Vitriol, gj 3j up- 
on Sublimation gives me the Sal fedativnm de- 
scribed by M. Homherg j and theRefidue expofed 
to a ftrong Fire affords Glauber's Salt. I have 
found out a Method to fhorten this Operation ; for 
Inftead of fubliming this Salt, I get it by Cryftalli- 
zation in light foliated Lamina. This Salt, whe- 
ther fubl imared or cryflallized, has the Property of 
diffolving in Spirit of Wine ; and if you fet this 
Spirit of Wine on Fire, its Flame is green. Spirit 
of Wine has no Effeft on Borax 5 the Oil of Vi- 
triol, digefted with Spirit of Wine, communicates 
no Greennefs to its Flame: therefore it is requifite 
that the Borax Ihould be united to an Acid, in order 
to produce this green Flame. 
P O S f S C R I P V. 
I Send you a Specimen of Salt made of Cryjldls of 
Tartar and Lime Water, which Meff rs . GroJJ'e 
and Duhamel , two Members of our Academy, have 
prepared ; to which I join Cryjtals of Seignette' s 
Salt, that M. Bolduc and I have made feparately. 
You will alfo find fome Sal Sedativum made by 
Cryftallization, which cryftallizes in a peculiar Man- 
ner. This Operation is perform’d with giv of Bo- 
rax, and gi 31 of concentrated Oil of Vitriol, the 
moft fixt and weighty that can be had. The Bo- 
rax is put into a Glafs Retort, the Oil of Vitriol is 
poured on it, and then half an Ounce of common 
Water. This Mixture being expofed to a Fire gra- 
dually encreafed, after the Phlegm has palled off. 
