BUREAU OF ANIMAL INDUSTRY. 147 



conclusion that Avhile the chh)rin disinfectants have a very valuable 

 place in the treatment of wounds and the purification of drinking 

 water, they do not seem to be well suited for general disinfection, 

 because the organic matter which is always present in large quanti- 

 ties quickly combines and renders the chlorin inert, and because 

 chlorin is injurious to metals and fabrics. The action of the chlorin 

 disinfectants was also tested on different disease-producing micro- 

 organisms. 



A comparative study of 15 samples of G brands of bacteriologic 

 peptone showed that these peptones varied very greatly in compo- 

 sition aiid that some of the peptones on the market were of such com- 

 position that a typical culture of Bacillus coli gave negative reac- 

 tions for indol when those particular peptones Avere used in the 

 culture medium. This work indicates that it is advisable to test 

 each new lot of peptone used in order to determine its suitability 

 for indol production. A test of the peptone for the presence of 

 tryptophane will usually show whether any given sample of peptone 

 is suitable for indol production. 



RESEARCH WORK ON MEATS AND MEAT FOOD PRODUCTS. 



Chemical research on meats and meat food products has consisted 

 chiefly in a study of the composition, nutritive Aalue, and whole- 

 someness of edil)le viscera from meat food animals. 



Thus far a chemical study of the livers of mature oxen and of 

 calves has been made. In addition to the usual proximate analj^sis 

 of this tissue, the percentage of each of the important mineral con- 

 stituents has been determined. A discussion of the results is reserved 

 until similar work with sheep and hog livers has been completed. 



The antineuritic properties of beef and calf liver were investigated 

 by feeding the dried liver in conjunction with polished rice to pigeons. 

 The results indicate that calf liver has a lower antineuritic value than 

 beef liver, though this difference may have been due to lower average 

 vitality of the pigeons used in the test with calf liver. Additional 

 experiments are planned to test the antineuritic value of liver as 

 well as other edible viscera from meat food animals. 



TUBERCULIN AND MALLEIN. 



There was supplied to Federal, State, county, and city officials 

 5,517,040 cubic centimeters of tuberculin for the subcutaneous testing 

 of cattle for tuberculosis. In addition 38,268 ophthalmic tuberculin 

 disks, 20.250 doses of liquid ophthalmic tuberculin, and 182,420 doses 

 of intradermic tuberculin Avere produced. The total output of tuber- 

 culin represents an increase of considerably more than 100 per cent 

 over that of the preceding year. 



The success obtained with ophthalmic tuberculin disks, which were 

 first produced in these laboratories, in testing cattle for tuberculosis, 

 has made it necessary to provide additional equipment and a specially 

 constructed room in which the humidity can be regulated. Tliis is 

 now practically complete and makes possible a large increase in the 

 quantity of ophthalmic tuberculin that can be produced. 



The quantity of mallein prepared and distributed for the diag- 

 nosis of glanders was 215,580 doses, as compared with a total of 

 2.930,810 doses the preceding year. This great decline is due to the 



