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Self-jilling Syphon for Chemical analysis. 



Art. XIV. — Self-filling Syphon for Chemical Analysis; by 

 William B. Rogers, Prof, of Chemistry, and Natural Phi- 

 losophy in William and Mary College. 



In Chemical analysis and other operations of the Laboratory, 

 where a large amount of liquid is to be removed from a vessel without 

 disturbing the precipitate which has collected on the bottom and 

 sides, a small syphon of glass may be very conveniently employed. 

 To commence the action however, as every one knows, the syphon 

 must be previously filled, and the introduction of it in this state is 

 apt to agitate the liquid and thus disturb the precipitate. Moreover 

 where accuracy is an object, the Instrument must be filled either with 

 a portion of the liquid to be removed or with distilled water, and 

 sometimes it would be inconvenient to do either. Having recently 

 had much occasion for the syphon in analysis, the following contri- 

 vance was adopted for obviating these little difficulties. Perhaps 

 others may find it useful and in that hope I send you a description 

 of it. 



To the long leg A of the syphon is 

 cemented or fastened by a cork a circu- 

 lar plate of thin, hard wood about one 

 inch in diameter iurnished with a little 

 projection at C. This plate is perforated 

 and embraces the end of the syphon. — ■ 

 Another similar plate placed below is 

 connected with the former by some flex- 

 ible material such as oiled silk, or thin 

 bladder, so that when the lower disk is 

 drawn down a hollow cylinder is formed. 

 The oiled silk or other material- may be 

 secured around the edges of the two 

 disks by any good cement, but of course 

 the joinings should be air tight. A 

 wooden valve P opening downwards and 

 about half an inch in diameter is attached 

 to the lower disk and closes an aperture 



