084 EXPERIMENT STATION RECORD. [Vol.38 



A brief report is made of an experiment in two Chicago district!?, in whicli 

 present metliods of millj delivery were compared witli a trial systematized, or 

 imified, delivery. In one of these districts, under present methods, 33G bottles 

 of milk were delivered in 337 minutes by eight different men representin,:: six 

 companies. Under the unified experimental delivery this milk was delivered 

 at the rate of 1.87 bottles a minute, or about 54 per cent of the time taken by the 

 present system. In the other district the efficiency of the present method as 

 compared with the trial delivery was just under 55 per cent. It is estimated 

 that under a unified system of milk delivery only 37 per cent of the horses now 

 used would be required. Other economies in such a delivery system are pointed 

 out. 



VETERINAEY MEDICINE. 



[Report of tlie veterinary department], J. W. Connawat, A. J. Durant, 

 and H. G. Newman (Missouri Sta. Bui. 151 {1911), pp. 59-61). — In continua- 

 tion of hog cholera immunity studies (E. S. R., 37, p. 779) investigations were 

 made of the duration of infectiousness of the blood of swine which have been 

 treated by the serum-virus method. Forty-six pigs were treated with the blood 

 taken from 9 immunized in this way, and it was found that the blood was regu- 

 larly infectious for 8 days after imiuunization ; that there was a variation in 

 the infectiousness after the eighth day ; and that the infectiousness ceased 

 after the seventeenth day. It is thought, however, that the inoculation of 

 larger doses of the blood would probably show the presence of active virus 

 for a period longer than 17 days. 



Studies made of the intra-vitam contamination of the blood of swine by 

 tubercle bacilli furnish proof of the possibility of transmitting tuberculosis of 

 the bovine type by blood inoculation from infected to other swine and to rabbits 

 and guinea pigs, as well as from rabbit to rabbit. 



In investigations of contagious abortion, 52 of 73 suspected herds of cattle 

 were found to be infected with contagious abortion. Of the 1,471 cattle tested. 

 516 gave positive reactions to the abortion test and 955 negative. Tests of 

 blood samples from 29 pure-bred brood sows in four herds in which contagious 

 abortion was suspected showed positive reaction to the complement fixation 

 test in 21 of the 29 tested. 



Peptone-free media for routine culture work, N. S. Feery and A. Nobi,e 

 {Jour. Lab. and Clin. Med., 3 {WIS), No. 5, pp. 298-300) .—Trinls with ten 

 different media without peptone, part of them neutralized and part made 1 per 

 cent acid, showed that for organisms which grow readily on standard plain 

 agar, neutral veal or beef media without peptone can be substituted. 



Serum veal agar: A dependable substitute for ascitic or blood agar, N. S. 

 Fekky and A. Noble {Jour. Lab. and Clin. Med., 3 {1918), No. 5, pp. 295-297).— 

 The authors have found that ascitic or blood agar may be successfully replaced 

 in most cases by a veal agar (neutral to phenolphthalein) to which has been 

 added normal horse serum. A formula for the medium is given. 



[The Abderhalden blood test], L. R. HiMiiELBEuoER and W. S. Anderson 

 {Kentucky Sta. Rpt. 1015. pt. 1, pp. 25, SO, 31).— The Abderhalden blood test 

 was made on a number of brood mares and it was found that pregnancy can 

 be determined in 80 cases out of 100. It is believed that with more experience 

 the test will become almost infallible. 



Owing to the fact that dialyzers could not be obtained, a modification of the 

 original method was employed, the serum proteins being precipitated out by 

 chemical means as follows : The placental protein and serum were placed in a 

 test tube covered with toluol and incubated for 16 hours. The contents of the 



