151 



The action of the lye on sonr milk i« hnstoned by adding it to the milk in small 

 (liiantiticH so that tho lyo is dissolved. ICont; half a ti-asjxionfiil of the lye is thrown 

 into the uiilk at once, it collects to^icthn- in a hard luuiji, which is dissolved witli 

 diftHiilty. Tho whole process of thinniii;^ the thick sonr milk with lye is aided l>y 

 warminj? the milk at a temperutnre of 1(K)^ to 140'^ F., and letting it stand for an 

 honr or more. The time and heat both help tho solvent action. Pourinjj from ono 

 jar to another is also an important factor in getting the milk thoroughly mixed. 



The rcsult.s arc ^ivcn for the tests iiuid*.* cudi day, with tlie avcrajics 

 of these tor the 7 days, and for the three sets of eomposite saini)les. The 

 lollowiiiy: comparison of the results by the different methods of sampling- 

 is taken from the bulletin : 



Average percentage of fat in milk hij different methods of sampling. 



Patron. 



1 

 2 

 :j 



4 

 5 

 6 



7 

 8 

 9 

 10 

 11 

 12 

 13 

 14 

 LI 

 lU 

 17 

 18 

 19 

 20 



Average 



of tho 



suven daily 



tests. 



Fer 



cent. 

 3.62 

 3.71 

 3.75 

 3.63 

 3.95 

 3.64 

 3.82 

 4.10 

 4.30 

 4.16 

 3.96 

 4.52 

 4.22 

 3.77 

 3.82 

 3.77 

 .{. 63 

 3.71 

 4.11 

 3.90 



Composite samples. 



Equul 

 amounts of 

 milk CiU'h 

 day, pois- 

 oned. 



Per cent. 

 3.6 

 3.8 

 3.7 

 3.8 

 4.0 

 3.7 

 3.9 

 4.1 

 4.3 

 4.2 

 4.0 

 4.6 

 4.4 

 3.9 

 3.8 

 3.8 

 3.7 

 3.8 

 4.0 

 4.0 



Amounts pro- 

 port ioniil to 

 tlie .luioiint 

 ot milk 

 brought, 

 poisoned. 



Fer cent. 

 3.6 

 3.7 

 3.7 

 3.6 

 4.1 

 3.6 

 3.8 

 4.0 

 4.4 

 4.2 

 3.9 

 4.6 

 4.4 

 3.9 

 3.9 

 3.8 

 3.6 

 3.7 

 4.0 

 4.0 



Equal 



amounts of 



milk each 



(lay, not 



poisoned. 



Fer 



cent. 

 .3.6 

 3.7 

 3.7 

 3.7 

 4.1 

 3.7 

 3.8 

 4.1 

 4.3 

 4.3 

 3.9 

 4.6 

 4.4 

 3.9 

 3.9 

 3.8 

 3.7 

 3.7 

 4.1 

 3.9 



It ^vill be seen that the agreement of the several series of comjiosite 

 sanqdes is very close, and that th<'se results present only slight varia- 

 tions from the averages obtainc<l by testing samples daily. It would 

 seem therefore that (1) "in this trial, testing the composite sample once 

 each week was practically as accurate as testing milk every day;" and 

 that (2) ''it is not necessary to use a ]»<)isoii for preserving the milk, 

 but that satisfactory results can be obtained by allowing the composite 

 sample to sour, and thinning the sour ndlk by use of ' powdered lye ' 

 when a test is to l)e made." The results of the tests each day show 

 considerable variations in the same milk from day to day, so that by 

 taking a single sample of each patron's milk oiice a week sufliciently 

 accurate results would not be obtaineil. 



Trials in which the sample of milk was taken by dillereut means, as 

 by dipping, by the " milk thief," by a small tube, and by a small tube 

 inside the delivery tube " indicate that there is practically nodifterence 

 in the methods of taking a sami)le of milk for testing, if ^jropcr care is 



