Polytechnic Association. 709 



Another point is the formation of clouds. He asks why the clouds 

 float. The vapor of water, as steam, has only one-half the weight of air. 

 A certain amount of vapor is taken up, and remains suspended in the 

 air ; and when the air is saturated, the excess drops out in the form 

 of rain. 



The further consideration of the subject was postponed until the 

 next meeting. 



The Woodson Steam Boiler. 

 Mr. F. A. Woodson exhibited a model of his improved steam 

 boiler, and explained its operation in separating the ascending from 

 the descending current, so as to prevent intermittent action, and equal- 

 ize the temperature of the boiler. 



Adjourned. 



December 15, 1871. 



Prof. S. D. Tillman in the chair; Mr. Robert Weir, Secretary. 

 The President read the following scientific notes : 



I. Carbonate of Soda. 

 A new process for the production of carbonate of soda has been 

 invented by M. Swager. By the joint aid of highly superheated 

 steam and red heat, he decomposes the double chloride of aluminum 

 and sodium, previously fused, thus forming aluminate of soda and 

 hydrochloric acid. The latter is condensed ; the former, heated with 

 carbonic acid, yields carbonate of soda and alumina. 



II. Red Phosphorus an Absorbent. 

 It is stated by Mr. Testini that the red variety of phosphorus has 

 the power of absorbing many substances without acting chemically 

 upon them. For example, this phosphorus, when powdered, is poured 

 into a violet-colored solution of iodine in bisulphate of carbon, and 

 on agitation the solution will become colorless, if a sufficient quantity 

 of phosphorus is present, thus showing that the iodine has been 

 absorbed. Sulphur, rosanaline and other substances have been absorbed 

 in small quantities by red phosphorus. 



III. Antidote to Phosphorus. 

 Messrs. Eulenberg and Vohl have shown that phosphorus is so 

 readily absorbed by carbon that, taken in the form of pills, carbon 



