1»20] VETERINARY MEDICINE. 881 



A proliminan- study of the cultural characteristics of the organism when grown 

 in the media used in thie previous study has led to the conclusion that for the 

 isolation of B. tetani anaerobic culture in alkaline broth (—10 or —20 on Eyre's 

 scale) is most satisfactory. In either case frequent platings out on agar with 

 an alkaline reaction are recommended. If the presence of the organism is sus- 

 pected, the inoculation should be made into a guinea pig. All isolated strains 

 should be grown in neutral broth for from' 4 to 8 days and inoculations made. 

 The cultural characteristics of the organism as thus isolated are described, and 

 a plate is included showing the appearance of 7- to 8-day colonies of the pure 

 organism on agar. 



The author recommends as the best medium for the production of tetanus toxin 

 neutral or slightly alkaline broth without the addition of glucose, and for the 

 preservation of strains in the laboratory for some time alkaline — 20 broth or 

 stab cultures in —10 agar, the tubes in either case to be sealed up. 



The precipitation of Bacillus welchii toxin, H. Henry and M. Lacet {Jour, 

 rath, and Bact., 23 {1920), No. 3, pp. 273-280).— On account of the instability 

 and low potency of B. tcelchii toxin as obtained in filtrates from meat-broth 

 cultures of the organism, a series of experiments was undertaken for the pur- 

 pose of obtaining a more stable form of toxin suitable for measuring the value 

 (»f sera containing antitoxin to B. welchii and at the same time a more potent 

 form for use in the production of antitoxic sera of higher titer than those as 

 yet obtained. 



The precipitating agents tested with cultures of B. welchii, filtered through 

 layers of paper pulp and sand and then through large Berkefeld candles under 

 pre.ssure, included ammonium sulphate in different concentrations, alcohol, and 

 ammonium sulphate followed by alcohol. The last method proved most satis- 

 factory, the secondary precipitation with absolute alcohol being carried out on 

 solutions of the precipitates obtained by two-tliirds ammonium sulphate satura- 

 tion. 



It has been found possible by this method to obtain solutions containing from 

 oO to 250 mouse minimal lethal doses per cubic centimeter as against from 

 5 to 10 mouse lethal doses by the ordinary methods. The toxin as thus pre- 

 pared underwent no deterioration during a period of 11 months when stored at 

 room temperature in amber colored bottles fitted with rubber corks. 



The efl'ect of the intradermal mallein test on subsequent complement 

 fixation tests for glanders, R. A. Kelseuj and J. G. Habdenbero, jr. {Jour. 

 Amer. Vet. Med. Assoc, 57 {1920), No. 3, pp. 282-29^) .—The possible effect of 

 the Interdermal mallein test on subsequent complement fixation tests was 

 studied on horses which had never received intradermal injections of mallein 

 previous to the experiment and on others that had previously been given several 

 intradermal tests. The technique employed was as follows: 



Healthy horses were bled for preliminary tests to demonstrate the absence 

 of complement-fixing bodies, and were then given Injections of either 0.1 cc. 

 or 0.2 cc. of army intradermal mallein into the lower palpebrum of the left 

 eye, after which they were kept in separate corrals and specimens of blood 

 taken daily, commencing 24 hours subsequent to the mallein injection and con- 

 tinuing for 21 days or longer if the animal still gave a positive reaction. Im- 

 mediately following the final bleeding a second injection of mallein was made 

 in the lower palpebrum of the right eye and the bleeding continued for the 

 same length of time. The serum obtained from the blood samples was tested 

 in the usual way for complement fixation, each specimen that gave any reaction 

 being tested from three to five times. The tests were controlled by simulta- 

 neous tests with negative sera from animals that had never been subjected to 



