334 R. Bunsen on the Washing of Precipitates. 
(of course diminished in size) of the original filter ; the flame 
is then increased, and the crucible maintained at a bright 
heat until the carbon contained in this envelop is consumed. 
The combustion proceeds so quietly that the resulting ash sur- 
rounding the precipitate possesses, even to the smallest fold, 
the exact form of the original filter. If the ash shows here 
and there a dark color, it is simply necessary to heat the cruci- 
ble over the blowpipe for a few minutes to effect the complete 
removal of the trace of carbon. This method of burning a filter 
is extremely convenient and accurate ; it is only necessary to. 
give a little attention at first to the slow carbonization of the 
paper, after which the further progress of the operation may 
to its 
Gelatinous, finely divided, granular, and crystalline precipi- 
tates, such as alumina, calcium oxalate, barium sulphate, sil- 
ica, Magnesium ammonium phosphate, &c., may with equ 
facility be treated in this manner ; so that even in this partic- 
ular the work, in comparison with the method generally 
adopted, is considerably shortened and simplified. 
rom the above experiments it appears that the time neces- 
the filter in a continuous stream, so rapidly that it is y 
possible to maintain the supply ; the entire operation, in fact, 
requires scarcely more time than that necessary to pour a liq 
4 ; may be ef 
valent to 02450 | 
’ on using the 
of alkali we should, by of about 
