218 Transactions of the American Institute. 



of the Mint, to investigate the subject ; he entrusted the investiga- 

 tion to Dr. Yersemann, who experimented on a great variety of sub- 

 stances, and found that tungstate of soda and phosphate of ammonia 

 were the salts best adapted to the purpose, the former being prefera- 

 ble to the latter. It is merely necessary to dip the fabrics into a 

 strong solution of this salt, and after drying to smooth them with a 

 hot iron as usual. I believe an enterprising grocer in London adver- 

 tised " lire-proof starch," which was simply a mixture of starch and 

 tungstate of soda to be used as a substitute for ordinary starch. 



In order to show you how effective this process is for protecting 

 fabrics, I have arranged these two muslin curtains ; this one has been 

 starched in the usual manner, and you will see how quickly the fire 

 runs through it when I apply the flame ; it is gone in an instant. 

 Now, you see I cannot set the other on fire ; it is prepared with tungstate 

 of soda ; it is merely charred where the flame is held in contact with 

 it. Here are two muslin dresses which, expanded on their wire 

 frames, call to mind our dear little treasures at home, who are con- 

 stantly exposed to danger from the inflammabilty of their clothes, 

 and the inclination to play with fire. There, you see one has disap- 

 peared in a moment, while I cannot cause the other to burn. I think 

 a fortune could be made by some enterprising person in supplying the 

 grocers with a " fire-proof starch," to be used for muslins. 



Rendering Timber Non-inflammable. 



This material can also be applied to timber to render it non-inflam- 

 mable. It is absorbed, and enters into the pores of the timber. 

 Lumber, to be used for building purposes, may be soaked in some 

 saline solution, and thus be rendered non-inflammable. Such wood, 

 if thrown into the fire, will be charred ; but it would be impossible 

 to set it on fire by itself. A solution well adapted for this purpose 

 is the silicate of soda, or soluble glass. 



Decay is Combustion. 



Another form of combustion is the decay of organic bodies 

 exposed to the air ; they undergo slow combustion, or oxidation, and 

 the products of this combustion are identical with those of rapid 

 combustion by fire. Carbon yields carbonic acid ; h} r drogen yields 

 water. 



Decay is of two kinds : that which takes place when the air has 

 free access, and that which takes place when air is excluded. The 

 first is simply slow combustion, and yields carbonic acid and water, 



