564 
Proceedings of the Royal Society 
No. 
i. 
ii. 
in. 
IV. 
y. 
VI. 
VII. 
Preparation. 
Made in earlier part of ) 
investigation, . . j 
Made at later part of 1 
investigation, . . j 
Made from same oxy- ) 
cyanide as No. II., j 
Made from same oxy- ) 
cyanide as No. II., j 
Made from another! 
preparation of oxy-> 
cyanide, . . . ) 
From another prepara- j 
tion of oxycyanide, 
rom another prepara 
tion of oxycyanide, 
Temp. 
at 
which 
Dried. 
Percentage of Bismuth. 
| By Ignition 
By Preci- in Air, and 
pitation as weighing 
Carbonate. 
150° 
300° 
300° 
300° 
300° 
250° 
250° 
i-7; 21-0 
25-5; 27-5 
Residue as 
Oxide. 
24-0 
7-08; 6-70; 
7-17; 7-77 
6-7 
Total Loss 
when 
Heated 
over 
Blowpipe. 
Per cent. 
73-4 
921 ; 91*4 
92-0; 918 J 
Percentage 
of Water; 
determined 
by Heating 
in Dry Air 
with CaCl 2 
Tube 
attached. 
1875; 
28-28 ; 
26-10 ; 
.31-0; 20-0 
16-9 
17-5 
( Burned with soda lime, gave 36-34 per cent. 
| N. =67*47 per cent. CN. 
f Burned with soda lime, gave 36 "32 per cent, 
j N.=67"45 per cent. CN. Burned with 
; CuO, gave 15-80 per cent. C. =34-23 per 
t cent. CN. 
From the three last determinations I conclude that the salt 
probably contains a considerable quantity of nitrogen, in addition 
to a large percentage of cyanogen. The variations in the quantities 
of bismuth found are remarkable ; to attempt the construction of a 
formula from these results would he useless. 
7. It has been already stated, that under certain conditions (see 
par. 4) the precipitate formed by the action of aqueous potassium 
cyanide on bismuth nitrate contains considerable quantities of the 
oxide Bi 4 O r ; also that the same oxide is produced by the action of 
hot concentrated aqueous potash on bismuth oxycyanide ; the for- 
mation of this oxide in the first of these reactions is almost certainly 
to be traced to a secondary change proceeding after the production 
of the oxycyanide. 
Various preparations of the new oxide were made; when 
thoroughly w T ashed with hot water the salt contains no potassium, 
it is very difficult to remove every trace of cyanogen ; after the 
analyses detailed in the following table had been made, it was 
