Smith.] 216 | Dec. 21, 
like cinder, which it was necessary to remove in order to obtain sufficient 
draft. It therefore appears, that although samples of this fuel can be selec- 
ted which will give favorable results upon the small scale, the mass of the 
vein can hardly be used for the general purposes to which anthracite is 
applicable, and that it requires some especial device for the removal of the 
voluminous ash, to enable the successful and coutinuous use of the fuel for 
ordinary purposes. 
CONTRIBUTIONS FROM THE LABORATORY OF THE UNIVER- 
SITY OF PENNSYLVANIA. 
No. XII. 
A new method for the Decomposition of Chromic Iron. By Edgar F. Smith, 
Ph. D., Assistant in Analytical Chemistry, University of Pennsyloania. 
(Read before the American Philosophical Society, December 21, 1877.) 
Recently I was led to try the action of bromine and sodium hydrate upon 
pulverized chromic iron, and as the amount of chromium extracted in this 
manner was rather surprising, the following experiments were made, to 
ascertain what effect bromine alone in presence of water would have upon 
the same substance. 
I. Moderately fine chromic iron (.1500 Grm.) was placed in a tube of 
hard glass, and after adding dilute bromine water and sealing the tube, the 
latter was placed in an air-bath and heated for twelve hours at a tempera- 
ture of about 130° C.; when cool the tube was opened and its contents 
poured upon a filter. The insoluble residue was thoroughly washed by 
decantation, and upon the filter, with hot water. The filtrate after con- 
centration was treated with a slight excess of ammonium hydrate, causing 
the precipitation of aluminum hydrate, &c. The latter was filtered off 
and the yellow colored filtrate, then warmed with hydrogen sulphide to re- 
duce the chromic acid to oxide. The precipitate formed, after protracted 
digestion, was allowed to settle and the clear liquid filtered. After wash- 
ing the precipitate it was dissolved in a few drops of dilute hydrochloric 
acid and re-precipitated. This operation was repeated and the precipitate 
finally transferred to a filter washed, dried andignited. The amount of chro- 
mium oxide found corresponded to 15.50 per cent, of the substance taken. 
The amount of chromium remaining in the material not attacked by the 
bromine was not estimated. 
II. .2000 grms, substance, as finely pulverized as could be obtained by 
grinding the material in an agate mortar, were heated ina sealed tube with 
water saturated with bromine and a few drops of bromine. The tube was 
allowed to remain in the oven for four days, the temperature ranging from 
175° — 190° C. Upon opening the tube its contents were poured into a 
