240 J. L. Smith on determining the Alkalies in Minerals. 
rid of the sal-ammoniac, and this brings me to the third part of 
this paper. 
IIL. The removal of the Sal-ammoniac unavoidably accumula- 
ted in the process of Analysis. 
23. ‘This is probably one of the greatest annoyances to the an- 
alyst in his examination of minerals; first, from the manner in 
which the salt creeps up the sides of the vessel in which the 
evaporation to dryness is carried on, and secondly from the great 
difficulty of preventing loss of the chlorids of the fixed’ alkalies, 
during the volatilization of the sal-ammoniac. A better idea is 
formed of this by an experiment with a known quantity of the 
alkalies mixed with sal-ammoniac. An array of the precautions 
requisite to be taken, can be seen in Rose’s last edition (German ) 
pages 6 and 7. Owing to these difficulties, which my experience 
has often led me to contend with, the method about to be men 
tioned was contrived ; it recommends vite both on account of 
its simplicity and eens of opera 
aving some e back disciced the decomposing of 
produced by heating ccatltioicectine with nitric acid, the n re of 
igated t 
made use of to decompose entirely the sal-ammoniac ; the result 
of the investigation was that the sal-ammoniac co ould be com 
pletely de ecomposed at a low temperature into ‘gaseous pro 
and it was immediately adopted in my analytical cape with the 
greatest ae both as to accuracy of results, as” ‘well as 
economy of la 
* Formation of eines pure Protoxyd of Nitrogen by the action. of Nitri itrie acid 0% 
Sal-ammoniac.—The experiments made y the nitric acid heated with baal scores 
niac, to test the character of the decomposition, have resulted in the discovery 
e troug e hot water, 
heat was applied to the flask, and before the temperature reached 140° Fah, # 
; © be given off, and at 160° it came off rapidly, and continued to do so chat 
the lamp was withdrawn. A small amount of red fumes appeared i in the flask, 
bil : 1 ected in are 
co 
experiment th the pr 
le: over hot distilled water, mnt a a sltion of caustic te ‘introduced and 
: ; this latter was subsequently analyzed for the chil wh 
y ‘oan three different portions, collected at the inning, middle wet 
of the process, rocess, the proportions of the chlorine to the whole bulk of the gas 
37 zg, and i. The amount of protoxyd of nitrogen due to the ammonia iD 
of sal-ammoniac and its equivalent of nitric acid, is oni cubic a es 
iia ved fax Geta being shaken up with cold water for 
