Chemical Analysis of Milk and its Products. 205 



results will thus be reached than by using an ordinary 

 Queveime lactometer. A thermometer is ground into 

 the neck of the specific-gravity bottle so as to form a 

 stopper, and the bottle is provided with a glass stoppered 

 side-tube, to furnish an exit for liquids on expanding. 

 A specific-gravity bottle holding 100 grams of water is 

 preferably used. The empty and scrupulously cleaned 

 bottle is first weighed on a chemical balance. The bot- 

 tle is then filled with recently-boiled distilled water of a 

 temperature below 60 F. (15.5 C.); the thermometer 

 is inserted, and the bottle is warmed slightly by immers- 

 ing it for a moment in tepid water and left standing until 

 the thermometer shows 60 F. ; the opening of the side 

 tube is then wiped off and closed with the stopper, and 

 the water on the outsi'de of the bottle and in the groove 

 between its neck and the thermometer is wiped off with 

 filter paper or a clean handkerchief, when the bottle is 

 again weighed. The weight being recorded, the bottle is 

 emptied and dried in a water oven, or if sufficient milk 

 is at hand, the bottle is repeatedly rinsed with the milk, 

 the specific gravity of which is to be determined. It is 

 then filled with milk in a similar manner as in case of 

 water; the temperature of the milk should be slightly 

 below 60 F. and is slowly brought up to this degree 

 after the bottle has been filled, proceeding in the same 

 way as before with water; the weight of the bottle and 

 milk is then taken. 



The weights of water and of milk contained in the 

 specific-gravity bottle are found by subtracting the 

 weight of the empty bottle from the second and the third 

 weights, respectively, and the specific gravity of the milk 



