Chemstry und Physies. 403 
tion became blue in all cases, when the U tube was cold as when 
it was heated to 100°. The addition of a second tube containing 
umice saturated with sodium carbonate did not alter the result. 
© test the effect of heat, an apparatus was used consisting of a 
large U tube containing pumice and sulphuric acid, a narrow U 
tube, which could be placed in a test tube, a weighed tube con- 
taining pumice and sulphuric acid and a flask with potassium 
i d. From one to five liters of 
‘ e second U tube was weighed after each experiment, 
and the starch solution was decolorized by a deci-normal solution 
of sodium thiosulphate. The maximum increase in weight in 
twenty-four experiments was ‘0035 gram, in an experiment at ordi- 
nary temperatures, the decolorization requiring 3°65 c.c. of the thio- 
sulphate. At 200° the sulphuric acid increased in weight °0006 
gram, the decolorizing solution used being 1°8 ¢.c. Since one 
¢.c. of this solution corresponds to *017 gram hydroxyl, whic 
gram instead of -0006 ee might have been expected had 
"3 ap 
2. Hxplosion of a Platinum Alembic used for concentrating 
Sulphuric acid.—Kuutmann (fils) has communicated to the 
Chemical Society of Paris the particulars of the explosion of a 
platinum still used in his factory at Lille, for concentrating sul- 
phuric acid. The still was 90 centimeters in diameter, and could 
concentrate 6 to 7000 kilograms of acid in twenty-four hours. 
e explosion scattered the fragments of it to a distance of 
The acid had nearly all been withdrawn from the still, a layer five 
centimeters deep, thirty or forty kilograms, being left in the 
t 
ee 3 o . avre and 
Silbermann and others, one kilogram of acid added to a suitable 
