306 Chittenden and W hitehouse—Metallic 
Series lV. 
With CuSO, 
No. Amt. sub. taken. Wet. CuO. Per cent. Cu. Wt. Cu.S. Per cent. Cu. 
la 0:3621 gram. 0:0047 gram. 1°02 0:0038 gram. 0°82 
b 0°3478 0:0046 1:03 00039 0°89 
2a 0°4318 0-0060 1:08 00040 0-71 
b 0°3288 00047 1°12 00033 0-78 
3a 04083 00060 1°15 0:0047 0:90 
b 04332 (0):0064 1iy 00053 0-96 
4a 0°3874 00047 1:09 00042 0:97 
b ():4289 00062 1:14 00050 0°90 
With Cu(C,H,0,).. 
5a 0°6358 ~ * 0-0090 Pela. 00073 0-91 
b 0°5147 00071 1:08 0:0064 0:99 
6a 0°5321 0-0075 1:12 00065 0°95 
b 05125 00073 1:13 okt. ao, 
Ta 0-7260 00125 1:36 Lee Bhat 
b 06916 0:0120 1:37 0:0100 1°15 
Series V. 
With CuSO. 
1a 0:4838 gram. 0°0083 gram. 1°36 0:0074 gram. 1°21 
b 0°5083 00091 1:41 ate ree 
With Cu(C,H,0,),. 
2a 0°5044 00085 1:32 apne soe 
b 0°5042 00084 1°32 
From the analyses of these 15 preparations it is to be seen that the 
percentage amount of metallic copper, determined as oxide by simple 
ignition, amounts on an average to 1°17 per cent. When, however, 
the copper is determined as subsulphide, by precipitation with hydro- 
gen sulphide, and thus obtained free from ash, the percentage amount 
of copper falls on an average to 0°94 per cent. Cu. The preparations 
thus contain 0°23 per cent. of ash. We were not able to obtain 
any copper compounds with a much smaller content of ash than this, 
except by the use of methods which appear to affect the composition 
of the compound. 
a 
