J. P. Cooke, Jr., on Lecture Experiments. 193 
which should therefore have a bearing on the glass of at least 
half an inch. It will be noticed that while the overflow tube 
5. 6. 
| 
is straight, the delivery tube is bent so that its open 
€nd is four or five inches above the mouth of the ab- 
ate made by boring with a cork-borer nearly through an ordinary 
Stopper and then pulling out the rubber core with a pair of 
Pincers, The absorption tube should now be divided into two 
Parts of equal capacity by means of rubber rings having how- 
Be: ieee of three or four inches at the lower end for the 
dent liquid. : 
agli absorption tube having been prepared as described and 
tilled With the mixed gases, the experiment is made in the fol- 
-Wing way. The apparatus is first rapidly depressed in a solu- 
tion of caustic soda (of the ordinary strength used in the lab- 
: rail until the liquid rises in the tube to the level of the first 
how Perfectly air tight, is removed from the liquid and the solu- 
Aw. Jour. Sci—Sxcoxp SznrEs, Vor. XLIV, No. 131.—Surr., 1867. 
25 
