336 Description of an Apparatus for the 
Art. XVII.—Engraving and Description of an Apparatus for 
the Decomposition and Recomposition of Water, employed in 
the Laboratory of the Medical Department of the University 
of Pennsylvania ; by R. Hare, M. D., Prof. of Chem. Read 
before the Amer. Philos. Society, Dec. 7, 1838. 
Havine to illustrate the decomposition and recomposition of 
water to a class of between three and four hundred pupils, I have 
found it expedient to exh.bit the process on an extensive scale. 
For many years I have employed a glass tube, of about an inch 
and a half in bore, and about two feet in height. 
The tube (A), which I have used for three years past, has been 
furnished with two tubulures (B, 5), about three inches below the 
upper extremity, where it converges to an apex, having an aper- 
ture not larger than a goose quill. Upon this apex there is an 
