VETEKINAKY SCIENCE AND PRACTICE. 393 



for rabbits. Antiricin serum wan obtained by immunizing a goat. After one series 

 of injections witli the solution of ricin 1 cc. of the serum of tliis goat was sufficient 

 to neutralize the action of 0.5 cc. Later, after another series of injections, 1 cc. of 

 the serum neutralized 1 cc. of the ricin and still later 2 cc. An extensive series of 

 experiments was made in which various mixtures of these 2 substances were used. 

 During these experiments it was found that the formation of precipitates in the mix- 

 tures in different proportions of ricin and antiricin, as well as tlie variable properties 

 of the mixtures containing identical quantities of toxin and antitoxin, and Hnally the 

 at once antitoxic and toxic properties of these mixtures in any proportion proved 

 beyond question that these 2 substances tix or impregnate each other reciprocally in 

 variable proportions. When mixed together, toxins and antitoxins do not form a 

 simj)le compound but rather a series of compounds in which one of the substances is 

 more or less impregnated by the other. The mixtures are therefore more or less 

 active. 



Agglutination in cases of mixed infection and the diagnosis of these infec- 

 tions, A. Castellaxi (/.tM-hy. ILjg.u. Iiifectionskranl'., 40 {1903), No. 1, )>p. 1-30). — 

 A brief review is given of the literature relating to this subject. The author's experi- 

 ments included a study of mixed infections produced hy simultaneous injection of 

 different micro-organisms, the agglutination which occurs when a secondary infec- 

 tion is added to an already existing primary one, agglutination in mixed infection in 

 man, and the diagnosis of mixed infections with the aid of the agglutination test. 

 The results of these experiments indicate that in cases of experimental mixed infec- 

 tions which are produced simultaneously, the blood serum acquires an agglutinating 

 power toward all micro-organisms with which the animal is inoculated. The begin- 

 ning, the intensity, and the duration of the agglutination for each kind of organism 

 are the same as in animals inoculated with but one species alone. When a secondary 

 infection is added to a primary one near the beginning or toward the end of the lat- 

 ter the blood acquires an agglutinating j^ower for the organisms of both infections, 

 and this power does not differ from that which is manifested in case of simultaneous 

 mixed infection. 



Tuberculosis, E. von Behking, P. Romer, and W. (i. l\i tpej, {Beitr. Kvj/er. 

 Ther., 1902, No. 5, pp. 90, figs. 42). — The experiments for the purpose of perfecting a 

 method of immunizing cattle against tuberculosis have been carried on at the Insti- 

 tute for Hygiene and Experimental Therapy of the University of Marburg for a 

 number of years, and have led to results of great importance from a practical as well 

 as a scientific standpoint. The most important conclusions which are drawn from 

 these investigations are that cattle can be perfectly immunized against tuberculosis; 

 that tuberculosis of man and cattle is one and the same disease; that the agglutination 

 method for recognizing tuberculosis, as proposed by Arloing and as modified by von 

 Behring, is unsatisfactory; and that mammals upon which experiments have been 

 made may be arranged with regard to their susceptibility to tu])erculosis in the fol- 

 lowing order, beginning with the most susceptible: Guinea pigs, rabbits, dogs, goats, 

 cattle, horses, sheep, and white mice. During the experiments which are described 

 in the present report, and wliich extended over a period of more than 5 years, an 

 exceedingly virulent form of tubercle culture was produced which killed cattle 

 within 2 or 3 weeks, under symptoms of miliary tuberculosis. This culture was 

 used for testing the degree of immunity of animals which had been treated, and also 

 for testing the susceptibility of the control animals. It was found possible to secure 

 cultures of tubercle bacilli of ahnost any origin sufficiently attenuated to produce a 

 mild form of the disease in cattle, and thus to confer upon them a lasting immunity. 

 All cultures of bacilli of different origin are, however, not equally well suited for use 

 in immunizing cattle. For practical purposes the authors recommend that neither 

 tubercle bacilli of bovine origin nor those from human patients which have been 

 increased in virulence by passage through cattle or goats should be used in attempts 



