138 Immunity 



the other after twenty-four hours in the ice-box, both observations being made 

 on the same series of tubes. Hemolysis is shown by the appearance of a beauti- 

 ful clear red color of the formerly cloudy greenish suspension. One must notice 

 the diflference between partial and complete hemolysis, different additions of the 

 hemolytic substance being required for these results. 



Cytolysis. — The phenomena of hemolysis correspond to those 

 by which many other cells, vegetable and animal, are destroyed and 

 dissolved through the activity of immunity product. Delezene* 

 first produced a leukolytic or le^kocyte-destroying serum by in- 

 jecting animals with the leukocytes of a heterologous species; 

 Metalniko2,t by injecting the spermatozoa of one animal into 

 another of different species, produced a spermatoxic or spermalytic 

 serum; von Diingern,J a serum capable of dissolving the ciliated 

 epithelium scraped from the trachea of an ox by injecting the dis- 

 sociated epithelial cells into an animal. Delezene§ found that 



Fig. 22. — Latapie's instrument for preparing tissue pulp. 



by injecting an animal with the dissociated liver cells of a heter- 

 ologous animal, a hepatolytic serum could be produced. 



The technic of these investigators is not difficult. It is, however, first neces- 

 sary to prepare a homogeneous tissue pulp for injection into the animal that is 

 to furnish immune serum. For this purpose it is necessary to grind the tissues, 

 when solid, in some kind of mill, one of the best froms of apparatus being that 

 of Latapie.ll After the pulp is made, it is diluted to a convenient extent with 

 physiological salt solution and then injected into the experiment animal in the 

 same manner as is the blood for making the hemolytic serum. After the animal 

 has received a number of injections made at intervals of a few days and is thought 

 to be "immunized" it is bled and the serum separated. The remaining steps 

 in the experiment do not differ essentially from those of hemolytic experiments. 

 The tissue suspension, having about the same concentration as the 5 per cent. 

 NaCl suspensions of the corpuscles, is used as the constant quantity and the 

 immune serum used as the variable quantity. The tissue suspension or antigen, 



* "Compt. rendu de I'Acad. de Sciences de Paris," 1900. 

 t "Ann. de ITnst. Pasteur," 1899. 

 i "Miinchener med. Wochenschrift," 1899. 



§" Compt. rendu de I'Acad. de Sciences de Paris," 1900, cxxx, pp. 938 and 

 1488. 

 II "Ann. de ITnst. Pasteur," 1902, xvi, p. 947. 



