ANALYTICAL PROCESSES. 



SPECIFIC GRAVITY. 



Determinations of specific gravity of milk are un- 

 derstood to be taken at the temperature of 6o°F., and 

 samples at temperatures different from this should be 

 brought to it. If at a few degrees above or below 

 60° it will suffice to take the gravity at once, and obtain 

 the correct figures by reference to Table A. 



The specific gravity of normal milk varies be- 

 tween 1028 and 103s, being less in porportion 

 as the fat is greater. A milk, the specific gravity 

 of which has been raised by the abstraction of 

 fat (skimming) can be restored to the original specific 

 gravity by the addition of water, so that this figure 

 taken alone cannot be relied upon as an index of the 

 character of the sample. Taken in conjunction with 

 the figure for fat or for total solids, it is of the 

 greatest value, and should be ascertained as a check on 

 the results furnished by other determinations. 



Air bubbles are held rather tenaciously by milk and 

 care must,thefefore, be taken in mixing the samples pre- 

 paratory to taking the density, to avoid as far as possible 

 the enclosure of air, and to allow sufficient time for the 

 escape of any bubbles that may be present. 



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