SPECIFIC GRAVITY ESTIMATION. 



75 



to be subtracted is 1-1, giving the specific gravity corrected 

 to 60 F. as 32-9 = 1-0329 ; or if the temperature is 66 and 

 the specific gravity 29, the correction to be added is 0-8 and the 

 specific gravity is 29-8 = 1-0298. 



Never take the specific gravity of a milk without also 

 noting the temperature and correcting to 60 Fahrenheit. 



Instead of reading from the bottom 

 of the curve and making a mental 

 allowance, the lactometers may be read 

 from the top of the curve and a definite 

 figure (ascertained by a few carefully- 

 conducted experiments) added on. 



As soon as the specific gravity and 

 temperature have been taken, the 

 corrected specific gravity from the 

 table should be entered in the book 

 provided for the purpose of recording 

 the results. It is not necessary to 

 enter the specific gravity in full, but 



Fig. 7. Glass Jar. 



Fig. 8. Lactometer in Milk. 



only the three significant figures ; thus a specific gravity of 

 1-0325 may be entered simply as 325 or 32-5. 



Though the determination of specific gravity has been de- 

 scribed first, it is found when total solids are to be estimated 

 that it is convenient in practice to proceed as soon as work is 

 commenced with their estimation, as this is an operation which 



