160 HATCH EXPERIMENT STATION. [Jan. 



sides and stopper of the retaining vessel must be incorporated, 

 and the resulting mixture should show no solid particles of fat. 

 A small fine wire sieve is of great value in detecting the imperfect 

 (lumpy) condition of a sample and in preparing the same for 

 pipetting. 



2. Pipette immediately after preparing the sample, filling the 

 pipette slowly, and taking care to avoid air bubbles. Hold the 

 pipette in a vertical position when lowering the liquid to the mark, 

 and always read with the entire meniscus above the line. In 

 transferring milk or cream to the test bottles, avoid, so far as 

 possible, the smearing of the entire neck with the liquids. 



3. Cream testing above 25 per cent, of fat should always be 

 weighed, as accurate results cannot be secured with the pipette. 



4. In adding the acid, turn the bottle so as to wash down all 

 milk or cream adhering to the sides of the neck, and mix at once. 

 Rotate the bottle until all the lumps of casein are thoroughly dis- 

 solved, and the resulting mixture is black in color. Never slight 

 the mixing, and avoid throwing the fat up into the neck. 



5. Whirl at least five, two, and two minutes. In filling with hot 

 water, allow the water to run down the sides of the neck, and thus 

 avoid stirring up the contents of the bottle. 



6. In reading the column of fat, it is safer to use a pair of 

 dividers than to trust to the unaided eye ; read the centre of the fat 

 column from the lowest to the highest limit. 



Inspection of Machines. — The inspection of Babcock ma- 

 chines, in accordance with section 3 of the law, is now in 

 progress. Mr. Nathan J. Hunting, a graduate of the col- 

 lege in the class of 1901, is charged with the execution of 

 this work. It is not possible at present to make any def- 

 inite report, other than to state that a number of machines 

 have thus far been condemned and others have been ordered 

 repaired. 



F. Miscellaneous. 



Under this heading it is desired to call attention to the 

 compilation of analyses of cattle feeds and dairy products 

 prepared by Messrs. Holland and Smith, and published as 

 Part III. Tables of a similar character were printed in the 

 ninth report of this station. The present compilation — 

 representing the analysis of different substances made since 

 the establishment of the Massachusetts State Experiment 



