100 
HYDROCYANIC-ACID GAS FUMIGATION IX CALIFOBXIA. 
except, of course, on a small scale, and provision was made for the 
collection of the liberated hydrocyanic acid that it might be quanti- 
tatively determined. Figure 13 shows a cut of the apparatus employed 
for this purpose. On account of the inability to control the large 
volume of gas which is so rapidly generated when the solid eyanid is 
all added to the acid at one time (as is done in actual practice) it was 
necessary to add it slowly, and hi order to do this the charge was dis- 
solved in water. 
DESCBIPTIOX OF APPARATUS. 
"A" is a flask of about 100 cc capacity into which the chemicals 
are placed for the generation of the hydrocyanic-acid gas; "B," 
Fig. 13.— Apparatus used in the decomposition of cyanids and collection of the liberated hydrocyanic- 
acid gas. (Original.) 
"C, " and "D" are DrechseFs gas wash bottles, and into each is put 
about 100 cc of a dilute solution of potassium hydrate to absorb the 
gas. Bottle "F" contains a potassium hydrate solution to free the 
air that is drawn through from carbon dioxid, which decomposes 
cyanids in solution when passed through them. "E" is a condenser 
containing cold water to cool the gases before reaching "B'' and 
thus prevent heating the solution in "B," which would cause decom- 
position of the potassium eyanid formed. 
DETAILS OF MANIPULATION. 
To "iff' add 10 cc of water, then 10 cc of concentrated sulphuric 
acid, after which add immediately to the separators funnel 5 grams 
