932 EXPERIMENT STATION RECORD. 



doses, 30 cc. of tuberculiu, were injected [into a healthy cow]. The second and 

 third injection with tuberculin of No. 145 and 161, diseased respectively, caused no 

 appreciable rise of temperature, but there was a decided decrease in the amount of 

 fat. [In the second test of the lot of 8 condemned cows], however, the 2 animals 

 that showed no rise in temperature failed to show any decrease in the milk fat. 

 When the rise of temperature was noted in the others a marked decrease in fat was 

 also noted. 



"A comparison of the decrease in fat with the extent of the disease, as revealed 

 by autopsy except in case No. 234, a generalized one, does not apparently show any 

 relationship. The oldest cases seemed to give the least change in fat, while the 

 newer cases gave the largest variation. . . . 



•■'The variation in fat should, of course, be attributed in part to the fever. But 

 that this is not the only cause is also evident. The variation is not, judging from 

 the few tests made, sufiScient of itself to prove the presence of tuberculosis, but 

 taken in conjunction with the rise of temperature might be considered as corrobora- 

 tive evidence." 



The opinions of the Paris Committee and the International Congress 

 of Veterinary Medicine, at Berne, on the value of tuberculin are cited. 



"The statement that the tuberculin injection causes the disease to spread more 

 rapidly is not warranted by facts, and in many instances the use of tuberculin has 

 a))parently caused an improvement in the disease. . . . 



"No. 285, an animal condemned for tuberculosis about a year ago, has been kept 

 at the station since that date. At first she was injected with small doses of tuber- 

 culin until she ceased to give a reaction and was again apparently Avell. The injec- 

 tions of tuberculin were increased in number and quantity, and on March 20, 1895, 

 the date of the last examination of the milk, the animal received an injection of 

 100 cc. Previous to that date she had received altogether 565 cc. of tuberculin. The 

 last injection caused no change in the amount of fat or in the temperature." 



A comparison of the Babcock test and the gravimetric method 

 of estimating fat in skim milk, E. H. Farrington ( Wisconsin 

 Sta. BuL 52, pp. 3-7, Jigs. 15). — The object of these observations was 

 to show as nearly as possible by drawings just what fraction of a per 

 cent is represented by the few globules of fat in the neck of the test 

 bottle in testing skim milk containing a minimum amount of butter 

 fat. Samples of skim milk Avere tested by the Babcock method and 

 the fat also estimated by gravimetric analysis for comparison. The 

 results of these comparisons are figured. 



It is considered impracticable to attempt to estimate less than 0.05 

 per cent of fat by the Babcock test. 



Two bottles are illustrated which have been devised for testing 

 samples of buttermilk or skim milk, one holding twice the usual 

 quantity of milk and acid, and the other having a double neck. The 

 result.s of comparisons of the Babcock test and the gravimetric 

 method on 12 samples of skim milk, using the double-neck bottle, are 

 tabulated. 



"The double-necked bottle is provided with a much finer graduated tube for 

 measuring the fat than any other test bottle. Each division is so long that fractions 

 of 0.1 per cent can be estimated as the graduations represent 0.05 per cent fat. . . . 



The double-necked bottles gave results which agreed very well with the gravi- 



