406 Experiments on the Combinations of 
cluded that the loss of weight of common fused potash and _ 
soda, during their combination with acids; depends upon the 
expnision of water, which M. Berthollet has rated at 13°9 
per cent. for potash, and M, D’Arcet»iat 27 or 28 for potash, 
and 28 or 29 for soda *.. i hotsed bes bisa: 
T have stated in the last Bakerian Lecture, that ‘my own 
results led me to conclude, that fused potash contained about 
16 or 17 parts in the 100 of water, taking the potash formed 
by adding oxygen to potassium as ‘a'standatd. 
The experiment from which I drew any conclusions, was 
made on the action of silex. and*potash fused together, and 
T regarded the loss of weight as the indication. of the quan- 
tity of moisture. 
Tam acquainted with no experiment on record, in which 
water has been actually ‘collécted ‘from "the ignited fixed 
alkalies, and this appeared necessary for, the complete eluci~ 
dation of the subject. Sod 4eds boot s7sd Yo .tnsk Get 6 jac 
I heated together in ‘a @reen ‘Glass retort; 40° erains of 
- sie sGFagtiwyd Sto 2lugoly edviw .9Se9 : 
potash, (that had been ignited for several aminutes,) and 100 
grains of boracie acid »whieh hac:been-heated ta whiteness 
for nearly an hours® Phe’retort wag ‘exrefully weighed, and 
connected with a small receiver, which. was likewise weiyh- 
ed; the bulb of the retort was then:gradually heated till it 
became of a cherry red; there'was'a ‘violent effervescence 
in the retort, a fluid condensed in the neck, and passed into 
the receiver. When the.processowas-eompleted, the whole 
of the retort was strongly heated 54 itowas found to have lost 
6} grains, and the’ feceiy Fubal Gale, .8 eran. The 
fluid that it contained -was, waiery:holskng-in solution ami- 
nute quantity of *bordernaeid piandowherp evaporated it did 
i dub awed os ted yet idoipw, s203 03. balsnitnoo , 
not leave an appreciable qui tity“Se ¥exiddam. vhgsu 
A similar reenaskad ice ‘upan-soda’ heated to redness, 
but in whichetheavatai collvited was'twt weighed, indicated 
29°9 of wate# in JOO BAUME SHUN 
It may be asked sebether .paxtof the water evolved in 
these processes-might'not have ‘been produced from the 
boracic acid, 6¢ ‘formed in, ‘Consequence of its agency; but 
the following. experiments show.that) this cannot be the 
case in any-sensible demreg, 90 saoinogor i 
T heated Sigrahas of Potassidih, With about 50 grains of 
boracte acid, to redness in a tube of platina, connected with 
a glass tube, -kept'very cools, but J found that no moisture 
whatever was ‘separated in the process. J mixed a few 
grains of potassium with red oxide of mercury, and ignited 
DIOR 
* Annales de Chimie, tome Ixviii. p. 199. 
the 
