ON MILK AND MILK-TESTING 37 



What points in the construction of skim-milk bot- 

 tles need special attention? 



1. The scale should be correct and the bore large 

 enough to admit milk or water freely. 



2. The glass should be tough and strong enough 

 to stand the pressure of whirling and the changes 

 of temperature. 



3. The top of the body should slant gradually 

 toward the center, with no uneven places where fat 

 might collect. 



4. The large neck should enter the body at the 

 base of the graduated tube and extend down 

 through the center of the body almost to the bot- 

 tom so that the acid will run under the milk and 

 not char part of it before they can be properly 

 mixed. 



How closely can percentage be read on a skim-milk 

 bottle? 



Some bottles are graduated to measure .01 per 

 cent while others read only as low as .05 per cent. 

 On either form one can distinguish easily varia- 

 tions of .01 per cent. 



Describe the different forms of Babcock cream test 

 bottles. 



1. Bottles with necks having a graduated 

 capacity from zero to 30 of 40 per cent and a body 

 so large that an 18-gram quantity may be used, 

 the graduations reading to i per cent or five-tenths 

 of I per cent. 



2. Bulb-neck bottles of the same capacity as 

 those above, but graduations reading to two-tenths 

 of I per cent. 



