The Bdbcock Test. 71 



81. Reservoir for water. When only a few tests are 

 made at one time, the hot water can be added with the 

 17.6 cc. pipette. If many tests are made, the water is 

 more conveniently and quickly filled into the test bottles 

 by drawing it from a small copper reservoir or tin pail 

 suspended over the testing machine. 1 The flow of water 

 through a rubber tube connected with the reservoir, is 

 regulated by means of a pinch cock (Fig. 10). The 

 water must be hot when added to the test bottles so as to 

 keep the fat in a melted condition until the readings are 

 taken. Some turbine testers are now made with a very 

 convenient water receiver attached to the tester (Figs. 

 23-24). 



The use of zinc or steel oilers, or perfection oil cans 

 has been suggested, as a handy and rapid method of 

 adding hot water to the test bottles. 



5. MODIFICATIONS OF THE BABCOCK TEST. 



82. The Russian milk test. The same chemical and 

 mechanical principles applied in the regular Babcock 

 test, are used in the Eussian milk test, except that in 

 this case the machine in which the bottles are whirled, 

 and the bottles themselves, are so constructed that the 

 latter can be filled with hot water while the machine is 

 running at full speed, thus saving time and trouble inci- 

 dent to the stopping of the tester and filling the bottles 

 by means of a pipette. The milk -measuring pipette 

 (Fig. 26) and the acid measure used in the Eussian test 



i Ordinary tinware rusts very soon when water is left standing in it, 

 and copper reservoirs are therefore more economical. 



