Polytechnic Association Proceedings. lOOY 



has made a good bronze by passing over highly h-eated oxyd of 

 copper the vapor of the petroleum product known as Rhigolene, 

 sixteen pounds of which will reduce two hundred pounds of copper. 

 After being allowed to cool in the same vapor it is lamellated in a 

 mortar. Various shades may be given to this powder by means 

 of the vapor. of zinc or cadmium. If the oil used in reducing the 

 oxyd contains a little sulphur, beautiful variegated colors will be 

 produced. The proportions of the metals ordinarily used are, for 

 a bright yellow, eighty-three parts of copper and seventeen of 

 zinc; for an orange, from ninety to ninety-four of copper, and from 

 six to ten of zinc. A red bronze is composed entirely of copper. 



COTTON WAX. 



Mr. E. Schunck, in a paper read before the Manchester Literary 

 and Philosophical Society, " on some of the constituents of cotton 

 fiber," describes the organic substances obtained by him from 

 unspun cotton yarn, the most interesting of which was a waxy 

 matter, insoluble in' water, but soluble in ether and alcohol. If a 

 concentrated solution in. boiling alcohol be allowed to cool, the 

 greatest part is deposited, causing the liquid to assume the appear- 

 ance of a thick white jelly, consisting of microscopic needles or 

 scales. When this jelly is filtered oif and dried, it shrinks very 

 much, and is converted into a coherent cake, which has a waxy 

 luster, and is translucent, friable, and lighter than water. Its 

 melting point is between eighty-three degrees and eighty-four 

 degrees C. At a higher temperature it is volatilized. "When 

 heated on platinum, it burns with a bright flame. The author 

 thinks it probable that this substance covers the cotton fibers with 

 a thin, waxy film, and this imparts to them tl»eir well known pro- 

 perty of resisting water. In its properties and composition it 

 approaches veiy nearly the vegetable waxes, such as those found on 

 the leaves of the sugar cane, and of the carnauba palm. He pro- 

 posed the name of cotton wax to distinguish it from other nearly 

 allied bodies. 



PLEUEO-PXEDISIOXIA. 



Many of the leading farmers in French Flanders have checked 

 the inroads of this formidable cattle disease by inoculation. M. 

 Barral visited the prize farm of M. Fievet, of Masny, who yearly 

 fattens nearly five hundred cows, in sheds containing two hundred 

 stalls, their feed being chiefly mangold refuse from beet sugar 

 works and distilleries, and observed the operation of inoculation, 



