BUEEAU OF ANIMAL. INDUSTEY. 249 



not treated in any way. The 18 serum- treated pigs and the 8 

 untreated pigs were then placed in the same pen with the 4 pigs which 

 had been made sick of hog cholera. The 4 pigs which were inoculated 

 with hog cholera all died. The 8 untreated check pigs all contracted 

 hog cholera from the 4 inoculated ones. The 18 pigs which were 

 given serum and which were confined in the same pen with the 4 

 original sick pigs and with the 8 untreated pigs which became sick 

 remained perfectly well and were finally turned over to the officials 

 of the stockyards company upon the completion of the experiment 

 on September 17, 1910. The experiment was witnessed by repre- 

 sentatives of the Nebraska Agricultural Experiment Station at Lin- 

 coln and of the Nebraska Swine Breeders' Association, as well as by 

 representatives of several different agricultural papers published in 

 Nebraska. 



The use of carbolized or phenolized blood, as described in my last 

 annual report, has been continued during the year. The later results 

 confirm the earlier observations in showing that the virus of hog 

 cholera may remain in contact with comparatively strong solutions 

 of phenol for weeks without noticeable impairment of its virulence. 

 There seems to be little doubt that phenolized blood will gradually 

 come into general use in connection with the "simultaneous method," 

 as the presence of the phenol prevents the development of putrefactive 

 bacteria and does not destroy the virus of hog cholera. This will 

 enable practitioners to keep virus on hand for a reasonable length of 

 time. 



Considerable study has been given to the effect of different preserva- 

 tive agents on the virus of hog cholera as contained in the blood of 

 sick hogs. In addition to the continued study of phenol much atten- 

 tion has been devoted to thymol and formaldehyde. The results 

 with regard to these, however, are not yet complete. Aside from the 

 desirability of having some means of preserving the virus for use in 

 simultaneous inoculations, it is also desirable to have some means of 

 preserving disease-producing blood which is to be used later for hyper- 

 immunization. Phenol is not satisfactory for this purpose, but it is 

 hoped that some efficient germicide which is efficient against ordinary 

 bacteria, but which does not materially affect the virus of hog cholera, 

 will be found suitable for this purpose. Some attention has also been 

 given to different preservatives for serum. These observations are 

 not yet complete. 



The study of the immunity possessed by young pigs has been con- 

 tinued, but up to the present time the data obtained are not suffi- 

 ciently conclusive to warrant a definite statement of results. 



WORK FOR THE COMING TEAR. 



During the ensuing fiscal year it is proposed to make a study of the 

 changes taking place in meat during cold storage, the object being to 

 decide upon the best conditions of storage and to ascertain whether 

 or not meat becomes unwholesome after storing for a long time. 



A study of the egg breaking and packing industries has also been 

 undertaken and is in charge of a committee consisting of the chiefs of 

 the Pathological, Animal Husbandry, and Biochemic Divisions. 

 Plans have been made for carrying on this investigation in coopera- 

 tion with a similar organization in the Bureau of Chemistry. 



