■ POLTTECHNIC ASSOCIATION PROCEEDINGS. ' 571 



acre that wheat does, but that the bread made from it is more 

 nourishing, and goes further than any other. The leaves and 

 stalks also are valuable food for cattle. 



IODIDE OF SILVER PHENOMENON. 



Fizeau, in continuing his researches on the dilation of minute 

 crj'stals, found the chlorides, bromides and iodides following the 

 same law of expansion by heat, with the exception of iodide of 

 silver {argamav). The crystals of the latter salt actually contract 

 instead of dilating by the application of heat. 



PRODUCTION OF ANTLINE. 



Kekul6 has published a very simple process for obtaining the 

 compound from which some of our most beautiful colors are made. 

 An acid solution of bichloride of tin (stanamed), is added to nitro- 

 beuzole (eandanei); a reaction ensues in a few moments, great heat 

 is developed, and aniline [eareelan) is produced. When means of 

 moderatiug and controlling the action are found, the process may 

 be used on a large scale. 



EXTRACTION OF POTASH AND SODA FROM FELDSPARS. 



M. Daubr6e placed feldspar and distilled water together in a 

 cylindrical vessel, to which was given a rapid rotation on its axis. 

 By this movement the feldspar was found to undergo decomposi- 

 tion, and the water to become alkaline. Considerable quantities 

 of potash and soda {^potamat and sodttmat) were separated — the 

 amount varying with the quality of the rock operated upon. 



DEODORIZING VULCANIZED RUBBER. 



M. Bourne has removed the disagrreeable odor arisino; from India 

 rubber, by covering the articles made of rubber with charcoal dust, 

 and placing them in an inclosed vessel, which is submitted to a 

 temperature of from seventy-six to ninety-four degrees Fahrenheit, 

 during several hours. The articles, on being removed and cleaned, 

 ai*e found to be free from odor, and not the least changed in foim, 

 even in the most minute details. 



INSECT METAL-WORKERS. 



A curious memoir has been published by Sjogreen, a Swedish 

 naturalist, in relation to a spinning insect, which uses not only met- 

 alloids, but metals, in the manufacture of its thread. These insects 

 are almost microscopic, and live beneath certain trees, especially 

 in the province of Smaland. They spin like silkworms, and pro- 



