of Organic Elementary Analysis. 163 
2.—0°1657 gram of chlorid of amyl gave 0°8314 of carbonic 
acid and 0°1608 of water. 
Calculated. Found. 
Carbon Ci, 60 563910 54°56 
Hydrogen” =H, 1) 10°3383 10°74 
Chlorine Cl 35°4 = 33°2707 
IV, Experiments with Oxyd of Copper, as absorbent of Chlorine in the 
analysis of substances rich in Hydrogen. 
In these experiments, for the reason previously stated, the oxyd 
of copper could only be placed in the anterior end of the com- 
bustion tube, where it might be maintained at a tolerably low 
temperature. After two or three experiments,—which were but 
partially successful,—it became apparent that the range of tem- 
perature within which oxyd of copper could be made serviceable 
to absorb the chlorine was probably rather limited. 
t was observed, for example, that at 150° to 160° even brown 
oxyd of copper, which had been but gently ignited, would fail 
to absorb nearly all the chlorine, and consequently the determin- 
ation of the carbon, and sometimes that of the hydrogen, would 
be in excess. In one experiment, in which the oxyd of copper 
was kept at about 153° C., its appearance had suffered no change, 
and it was found to contain only 8:29 per cent of chlorine, or 
only about one quarter of the theoretical quantity. When a 
sufficiently high temperature is employed, on the contrary, the 
posterior end of the column of oxyd of copper and asbestos has 
the appearance of being entirely changed into yellow chlorid of 
copper, the rest of the column remaining, for the most part, of 
its original dark color. 
In another experiment, with the oxyd of copper kept at a 
temperature of about 160°, only about fourteen per cent of chlo- 
rine was obtaine 
In both of these experiments the carbon determination was 
considerably in excess, and in one of them the hydrogen also. 
The oxyd of copper employed had been strongly ignited. 
Before proceeding further with these somewhat random exper- 
iments, it was deemed advisable to determine the temperature at 
which chlorid of copper begins to give off chlorine, in order to 
know how far it would be safe to raise the temperature of the 
air-bath in conducting an analysis. By making use of the air- 
bath to regulate the temperature of the chlorid of ones this 
determination was easily made. During the heating of the chlo- 
rid, a current of air from the air-gasometer was admitted through 
the tube in which it was contained. 
bservations.—At 243° not a perceptible trace of chlorine was 
givenoff. After the lapse of fifteen minutes, at 250°, the nitrate 
of silver into which the gas was conducted, was observed to be > 
