K. DOMESTIC AND HOUSEHOLD ECONOMY. 505 



stimulant, which tends greatly to favor digestion after a 

 meal ; and that, of course, the nutritive qualities of milk are 

 known every where. Whenever the two are mingled, how- 

 ever, we have a new compound, absolutely indigestible and 

 iinassimilable ; because, when in sufficient quantity and in 

 proper proportion, it forms a mass which entirely resists the 

 solvent action of the stomach. This is due to the amount of 

 tannin found in the coffee, which, when mixed with the milk, 

 transforms the albumen, or caseine, into a kind of leather, 

 precisely similar to a tanned hide. 3 B, June 19, 1873, 287. 



CHINESE PKEPAKATIOX OF SOY. 



Equal quantities of beans and wheat are boiled together, 

 and then triturated between stones, and water occasionally 

 added. The mass is cooked in a pan, and cut into thin slices, 

 which are kept covered with straw for about t^yenty days. 

 When completely fermented, the separate slices having be- 

 come mouldy, they are w^ashed with water, placed in a ves- 

 sel, and their weight of water and salt added. In this con- 

 dition they are kept for a number of days, and are finally 

 again triturated between stones. 32 (7, July 5, 1873, 345. 



PETEOLEUil FOR CLEANING GUNS. 



Petroleum, among other applications, answers an excellent 

 purpose for cleaning guns, it being only necessary to saturate 

 with it some tow wrapped around the end of the ramrod, and 

 to work this up and down a few times, and then remove the 

 tow and renew the application, and wipe out with dry tow. 

 The remaining film of the oil evaporates at once, and leaves 

 no moisture in the barrel to produce rust. The oil, how- 

 ever, must be perfectly free from sulphur and similar impu- 

 rities, as otherwise the metal will be attacked. 8 (7, 1873, 

 IX., 142. 



BURGLAK-PROOF SCREW. 



A screw, adapted to fastening locks, has been described by 

 Tucker. It has a right-hand wooden thread at the head-end, 

 and a smaller left-hand iron thread on the other end, or vice 

 versa, the latter being supplied with a nut. An effort to re- 

 move it from one side by unscrewing at the head only tight- 

 ens the nut, while an attempt to drive out the screw on the 



Y 



