746 Transactions of the American Institute, 



forming a brown-colored smoke, which, in a cooler part of the tube, 

 is condensed sometimes as amorphous silicon, sometimes in a crystal- 

 line state. The same occurs with boron ; but the apparent volatiliza- 

 tion is due to a simple mechanical effect, conjointly with the presence 

 of compounds of silicon with chlorine and flourine, which are only 

 formed at a very high temperature, and disassociated at a red heat. 

 It has been supposed that silicon and boron could not be brought into 

 a liquid or gaseous state. These experiments merely show that, under 

 certain circumstances, an apparent volatilization takes place. 



II. Preparation of Dextrine. 



O. Ficinus has described, in Dingier' s Polytechnic Journal, a cheap 

 mode of preparing pure dextrine. A mixture, consisting of 500 parts 

 of potato-starch, 1,500 parts of cold distilled water, and eight parts 

 of pure oxalic acid, is placed in a suitable vessel on a water bath and 

 heated until a small sample, tested with iodine solution, does not pro- 

 duce the reaction of starch. When this is found to be the case, the 

 vessel is immediately removed from the water bath and the liquid 

 neutralized with pure carbonate of lime. After having been left 

 standing for a couple of days, the liquor is filtered, and the clear 

 filtrate evaporated upon a water bath until the mass becomes quite a 

 paste, which is removed by a spatula, and having been made into a 

 thin cake, is placed upon paper and further dried in a warm place ; 

 220 parts of pure dextrine are thus obtained. 



Mr. T. D. Stetson — What becomes of the rest of it ? 



The President — It remains in the form of starch. Mr. J. Hirsh, one 

 of our members, was manufacturing starch very largely at Chicago 

 before the fire, but was burned out. He used principally corn, of 

 which he could buy cargoes in a partially damaged condition, which 

 answered every purpose for making starch. Oswego is another point 

 where large quantities of starch are made, and which affords the same 

 facility for procuring the materials at a low rate. Wheat is not much 

 used for starch. The principal substances used are corn and potatoes. 



III. Action of Heat on Germ Life. 

 T. Grace Calvert, in a paper " On the Action of Heat on Protoplasmic 

 Life dried on in Cotton Frabrics,"pnblished in the London Chemical 

 News, relates a series of experiments which have a direct bearing 

 on the question of the disinfection of fabrics arid wearing apparel in 

 heated stoves, with the object of destroying contagion or animalcule 

 life. To carry out these views, a piece of ordinary gray calico was 



