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Description of an Apparatus for the 



Art. XYII. — Engraving and Description of an Apparatus for 

 the Decomposition and Recowposition of Water, eniployed in 

 the Laboratory of the Medical Department of the University 

 of Pennsylvania ; by R. Hare, M. D., Prof, of Chem. Read 

 before the Amer. Pliilos. Society, Dec. 7, 1838. 



Having 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, 6), 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 



