230 ANNUAL REPORT OF THE Off. Doc, 



of dairj cows. It is at the expense of potential products and profits. 



Q. What should the over-run be to «how that the test has been 

 correctly taken? 



A. It is possible to make one-sixth more butter than there is fat in 

 the milk. This possibility, however, is not always attained. One- 

 seventh is entirely practicable. One-eighth excess is rather lees 

 than the average obtained at the creameries. If a creamery regu- 

 larly returns more than one-sixth, which is equal to 17 per cent, sur- 

 plus, the chances are that the tests are incorrectly made, or samples 

 incorrectly taken, or that a very wet butter is made. If, however, 

 the surplus is less than 12 per cent., which is equal to one-eighth, one 

 may look for loss in the manufacturing process through faulty work 

 or poor apparatus, or for incorrect test samples. 



Q. I would like to know whether Professor BLills considers the 

 method formerly in use for obtaining the total solids a correct one. 

 I refer to the lactometer. 



A. The lactometer is used to determine the specific gravity of the 

 milk. If, however, in addition a Babcock tester be used to obtain 

 the fat percentage, one may calculate the total solids using this 

 formula: T^1.2P+ (L"^4) +0.14. This formula is used as follows: To 

 one and two-tenth times the fat add one-fourth of the lactometer 

 1 eading and also 0.14. The result will give a close approximation to 

 the total solids providing the lactometer reading was taken at 60 de- 

 grees F. If it was not, the lactometer reading should be corrected 

 0.1 point for each degree of divergence, adding for a higher tempera- 

 ture and deducting for a lower temperature. 



Q. What is the correct specific gravity of the sulphuric acid used 

 in the Babcock test? 



A. 1.82 to 1.83. If the acid is not as strong as this, use more. If 

 it is stronger, use less. 



Q. I would like to ask an explanation of the statement regarding 

 nervous excitation causing deterioration of the milk. Is not the 

 milk already formed in the udder before the milking begins? 



A. It is in part, but just how much is a mooted point. There are 

 few places in this world as dark as the inside of a cow, and what we 

 do not know about the formation of milk w'ould fill a book. Indeed, 

 those investigators who have studied this question most deeply are 

 willing to admit that they know^ little or nothing as to how milk is 

 made. Theories abound, but proved facts do not exist. It is, how- 

 ever, a general belief that the solid portions of the milk and partic- 

 ularly the fat globules are to a large extent formed in what might 

 be termed their milk shape after the milking process had commenced. 

 At any rate there is much evidence that seems to corroborate this 

 notion. Certain it is that a deep milking Holstein, making, as some 

 have done, over fifty pounds of milk at a milking, does not appear to 



