Technical Chemistry—Photography. 425. 
Kopp, which have been published during the past year in Quesneville’s 
oniteur Scientifique. Not only do these articles furnish to the professed 
chemist a complete historical and critical account of the subject, but they 
also contain a full discussion of its technical details. Since the very 
completeness of Kopp’s memoirs must necessarily preclude the idea of 
transcribing them to our pages, we would here once for all call attention 
to their excellence.] 
1. Blast for Laboratory use—Dr. H. Sprencen has devised a com- 
bination of the Catalan-trompe and Maugham’s burner which appears to 
merit the attention of all chemists who have at command an abundant 
the syphon g being of similar 
lameter. The capacity of 
é flask A is about 1 litre [1 
quart == 1-14 litre]; it must 
provided with tightly fit- 
ng corks. Water being al- 
lowed to flow by opening the 
cock 2, a mixture of air and 
water reaches the flask A in 
The current of air flowing 
through & is conducted to th 
centre of a flame of street 
gas burning, at p, from the 
Opening of a Maugham’s 
burner, 
The arrangement of the burner may be seen more clearly in fig. 2. 
The gas enters at r, the air at.o. 
The conical tip p of the external tube is of platinum foil, but the other 
Portions are of glass, including the interior tube which is fastened to the 
ther by means of a cork. Special care is necessary in finishing the tip 
Since the beauty and regular form of the flame depends upon the uniform- 
ity of the fine opening. 
Jour Sct.—Srconp SERIES, VoL. XXXII, No, 96.—Nov., 1861. 
54 
