706 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



upward of 4,000,000 of these bodies must have been added to the 

 earth's mass. 



Heat feom the Combustion of Hydeogen. 



M. Schloesiug passed hydrogen gas, obtained from the decom- 

 position of water, over incandescent charcoal, and on to the pLace 

 of combustion, where it received the necessary oxygen from the 

 air — both the hydrogen and the air bciug reguhited in supply — 

 and thus produced the temperature of 2,700° C. or 5,198° Fahr. 



Effects of the Sfaek. 

 M. Lewis has found by a series of experiments and observations 

 with the microscope that the electric spark, however produced, 

 makes pentagon perforations. He has experimented with chem- 

 ically prepared paper, the leaves of plants, mica, thin glass, film 

 of eo'o", &c., and invariably finds a five-sided hole. 



Defective Leathee. 

 The sticky or gummy condition of some of the cheaper kinds of 

 curried leather, and its liability to crack, is said to be owing to the 

 use of fish oil in the finishing. Neat's-foot oil being the product 

 of the Ijovine species, seems to be naturally adapted to the tanned 

 skin, and the evils alluded to have only appeared where other oils 

 have been substituted by the currier. 



Ox the Blue Coloeation of ceetain Glasses and Slags. 

 M. J. Fournet, in a note to the French Academy, concludes that 

 this eifect is the pure and simple result of molecular grouping, of 

 which opacity — that is to say white enamel — is the final product. 

 By polishing pieces of blue bottle glass, varying in thickness, a 

 decided dichroism is observed — blue by reflection and oj-ange by 

 transparency. Generalizing the result of these observations, the 

 author shows that this dichroism belongs to many substances met 

 with in nature; corundum, phosphate of iron, pure water, and 

 clouds all show it under certain circumstances. The author does 

 not concur with the opinions of MM. Meue and Chevreul, which 

 we have recently recorded. 



New Mode of Moving Caxal-Boats. 

 An experiment has lately been tried on the Erie canal, near 

 Buffalo, which is said to have been quite successful. A wire rope 

 is laid on the bottom of the canal. By means of what is called a 



