Polytechnic Association Proceedings. 589 



May 23, 1867. 

 Prof. S. D. Tillman in the chair; J. Wtatt Reid, Esq., Secretary. 



The Chairman presented the following notes on progress in 

 science and art: 



ALUMINUM ALLOY IN DENTTSTRr. 



A process for casting an aluminum alloy has been invented 

 which will furnish a very light foundation for artificial teeth, not 

 afiected like gold, by sulphur compounds. 



FISH FEOM ARTESIAN WELLS. 



Sir Charles Lyell, in a new edition of his "Principles of 

 Geology," notices the discovery of fish in some of the artesian wells 

 sunk in the desert of Sahara. They were brought from the depth 

 of one hundred and seventy-five feet, and were not blind like 

 those of Adelsburgh, but had perfect eyes. 



NEW SULPHIDE OF CARBON. 



Loew describes a new compound, containing four atoms of car- 

 bon and one of sulphur, obtained by action of phosphoric persul- 

 phide upon acetic acid. It is insoluble in carbonic bisulphide, but 

 dissolves in concentrated sulphuric acid, and the solution has a red 

 color. The new name expressing the atomic constitutents of this 

 new body is eras. 



PROPAGATION OF CONCUSSION THROUGH GAS. 



M. Le Eoux, of France, has made experiments to ascertain the 

 rate at which a concussion is sent through a gaseous mass inclosed 

 in a tube, and maintained as near as possible at a uniform tempera- 

 ture. From seventy-seven determinations, he concludes that the 

 propagation is at the rate of 330.66 meters per second, wdth a 

 probable variation of one-sixteen hundredth of a second. 



LACTOSE. 



Dr. Fudaskowski, of Wtirtemberg, has separated pure sugar of 

 milk into two sugars by treating it with dilute sulphuric acid 

 (thelasot). Both are capable of fermentation, and both turn the 

 plane of polarization to the right. The one described by Pasteur, 

 crystallizes in hexagonal prisms and ferments more rapidly than 

 the other, which crystallizes in right prisms, and has a less sweet 

 taste. 



