eae a  — Rr 
Chemistry and Physics. 477 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHysics. 
On the Determination of Carbonic Acid in Mineral waters, 
P coaceens has proposed a new method for determining both 
the free and the combined carbonic acid of a mineral water. He 
uses in general the apparatus devised for this purpose by Classen 
but modified in its details to suit the new method. It consists of 
which two tubes pass; one a safety tube, ending near the bottom, 
through which hydrochloric acid can be pou ured and air aspiacat? 
the other attached to an upright condenser surrounded by a co oling 
cylinder. From the top of this condenser passes a rubber tube se a 
lapicating bottle. With this abparates three dain oi pies 
ments were made. In the first, hydrochloric acid of sp. gr. 1-06, 
was boiled in the flask for an hour, and then air free from CO, 
aspirated through it; the potash apparatus lost 0°0120 gram an d 
the soda-tube gained 0 00115 gram; thus proving the perfection of 
the apparatus. In the second, a measured volume of cold water 
Saturated with carbonic acid, was placed in the flask and gradu- 
ally heated to boiling, air being drawn through afterward. The 
increase of weight of the potash bulb and soda-lime ‘aha, ee 
) 
the side ge measure the quantity introduced. After connecting 
it with the apparatus the liquid is heated gradually to boiling, 
Sivbonts acid, reece the Selters Sate in this way, a liter of 
water gave free carbonic acid 2°4911 grams, combined 0°5699, 
total 3°0610 grams, against 3°0934 found by Fresenius. Ems 
