184 REPORT—1845. LO THT uO 
ealeined ore to analysis, according to the methods usually employed in such 
cases. The quantity used in the analysis was 2°324 grms., which yielded 
1-400 peroxide of iron, 0°153 alumina, 0°145 carbonate of lime, 0°202 phos- 
phate of magnesia, and 0°599 silica. In order to estimate the amount of 
potash, 17-936 grms. were ignited with carbonate of barytes, dissolved in mu~ 
riatic acid, and the bases, aiter separation of the silica, were as much as pos- 
sible precipitated by carbonate of ammonia. The solution was then freed 
from barytes by means of sulphuric acid, and the excess of the latter removed 
by evaporation with chloride of strontium. In this way the remaining bases 
were converted into chlorides soluble in alcohol, and the solution mixed with 
chloride of platinum and evaporated to dryness in the water-bath left a resi- 
due, which, treated with alcohol to dissolve out the other chlorides, consisted 
of pure chloride of platinum and potassium, and weighed 0°689 grm. This 
analysis gives the following composition for the calcined ore:— 
Siita a ee Peer eae pp 
Peroxide ofiron . . . . 60°242 
Atamind soos tts ce 6 Met es OOo 
' Lime . Sab ules 3°510 
Magnesia . a tla pial sl cc 
PGtash reer tere eee OT aes 
Manganese . - . - - -_ traces. 
100°000 
Another source of the potash was found to be in the coal, although to a 
iess extent than in the ore: 1°627 grm. of the coal, dried at 212°, yielded 
0°122 grm. of water; 0°2865 grm. gave 0°7865 grm. of carbonic acid and 
07153 grm. of water ; 2°887 grms., heated with the mixture of soda and lime, 
gave 0:0801 of chloride of platinum and ammonium. The experiment, re- 
peated with 5°687 grms. gave 0°175 of the above salt; 13:059 grms. of coal 
yielded 0°3505 grm. of ashes, which did not effervesce with acids; and this 
quantity of ashes, treated as in the case of the iron ore, gave 0°046 grm. of 
chloride of platinum and potassium. The coal therefore is composed as 
follows :— 
CMD atatel a Mea yiend ay, Abdi 
ELV ONG GN fd ek es tims te ode tpe pie edge 
ORV CNT facie ie 0 9 borne LOU 
INVERO RED oo ete is. sacle mae! s\ uy Ue 
WVALEE sie sala ven ins), Pon a pceniemmeieeh 
SLICALEE 9 Seen te ire. 6 de, sey tnp OL 
EAE Ye ee cei ha isin te ahah tule Ui 
100:00 
The quantity of ironstone consumed by the furnace every twenty-four hours 
is 33600 lbs., and that of coal 31200 lbs., so that the furnace receives every 
day in these materials 271°48 Ibs. of potash, corresponding to 377°3 lbs. of 
cyanide of potassium. Thus these analyses render intelligible the large 
quantity of potash which we observed in the inferior parts of the furnace. 
But we have yet to discuss the most interesting and important question bear- 
ing upon the presence of cyanide of potassium, viz. the origin of its cyanogen. 
We know how easily ammonia in contact with carbon at high temperatures 
is converted into cyanide of ammonium. Hence we should be apt at once 
to admit that the formation of cyanogen is due to the ammonia so freely 
evolved from the coal during its distillation; and if this view were correct, 
