VETERINARY MEDICINE. 579 



The investigation of defensive ferments by means of the Van Slyke 

 micromethod for the determination of amino nitrogen, H. Strauss {Ferment- 

 forsch., 1 {191Jf), No. 1, pp. 55-57). — In a large number of sera examined 

 according to the Abderhalden dialysis method a decided increase in the amount 

 of amino nitrogen, as determined by the Van Slyke method (E. S. It., 31, p. 610), 

 was obtained whenever there was a positive ninhydrin reaction. Experience in 

 the manipulation of the Van Slyke apparatus is deemed necessary for concordant 

 results. Possible sources of error and certain precautions necessary in the pro- 

 cedure are indicated. Experimental data show all positive results with preg- 

 nant sera. 



The excretion of antigen, Agnes E. Poktee {BiocJiern. Jour., 9 {1915), No. 1, 

 pp. 1-8). — From a series of experiments the author concludes that egg white 

 introduced parenterally into a rabbit is excreted unchanged in chemical prop- 

 erties. Three variations, however, regarding its specificity are possible: "(1) It 

 may retain partial properties as antigen, binding complement in the presence of 

 antiegg serum, not causing precipitation but capable of exercising an influence 

 over antibody so as to prevent it precipitating with fresh antigen; (2) it may 

 be excreted in a nonspecific form completely indifferent as antigen ; (3) it may 

 retain full antigen properties. 



" This variation in specificity of excreted albumin points to a physical rather 

 than a chemical explanation of the precipitin reaction." 



Detection and concentration of antigens by ultrafiltration, pressure dialy- 

 sis, etc., with special reference to diphtheria and tetanus toxins, A. T. 

 Glexny and G. S. Walpole (Biochem. Jour., 9 {1915), No. 2, pp. 298-308). — The 

 use of collodion-water membranes of a special type is suggested for the purpose 

 of forming a first opinion as to the specificity of the toxic element of any cul- 

 tural fluid. Mallein and tuberculin have been freed from glycex'ol and a large 

 quantity of nitrogenous material by this process. The essential steps in a 

 process for the concentration and purification of diphtheritic toxin, which at 

 a yield of from 70 to SO per cent diminishes the nitrogen content about 50 times, 

 are dialysis under pressure, followed by acidification, centrifugalization, and 

 re-solution of the small precipitate obtained in a trace of alkali. Ultrafiltration 

 followed by pressure dialysis gives a concentration of tetanus toxin which 

 should be of considerable practical value. The collodion membranes are imper- 

 meable to enzyms but allow secretin, the pituitary active principle, the coenzym 

 of zymase, and the toxic constituent of Witte's " peptone " to pass through. 



Experiments in vaccination against anthrax, A. Eichhorn ( U. 8. Dept. 

 Ayr. Bui. 3-iO {1915), pp. 16). — The prevalence of anthrax and methods of con- 

 trol, protective vaccination, and the production and standardization of the 

 serum are first dealt with by the author. Experimental data on the hyperim- 

 munization of horses and serum tests follow, together with a discussion of the 

 preparation of spore vaccine, a description of the technique of administration, 

 a test of the simultaneous method on cattle and sheep, field tests, the use of 

 serum treatment of anthrax in man, and concentration of the serum. In field 

 tests several hundred animals, including horses, mules, cattle, sheep, and hogs, 

 were treated with the Bureau serum and vaccine on farms where the disease 

 had broken out, without a loss. 



" The use of the serum-alone treatment is indicated in cases where the infec- 

 tion has already occurred in a herd. Since the serum confers only a passive 

 immunity, it is advisable to revaccinate the herd in from three to five weeks 

 by the simultaneous method. The serum possesses great curative value. De- 

 pending on the severity of the infection, the curative dose is from 30 to 100 cc, 

 the injection to be repeated if necessary. 



