158 Tests with Precipitins 



mediately to its antiserum. M'uller (18, II. 1902) dissolved lacto- 

 precipitum in boiling saline, and found that it could be reprecipitated 

 by fresh lactoserum, and also by rennet ferment. He considers that the 

 precipitum consists of unaltered casein combined with the precipitin. 

 Finally Fuld (1902) also found lactosera to act upon boiled milk. He 

 considers that the casein is chiefly concerned in the reaction. He 

 found the presence of lime salts essential. Contrary to Moro, he 

 was unable to obtain an antiserum from rabbits treated with boiled 

 milk. This difference, it appears to me, may very well be due to the 

 milk being " boiled " in a different manner by the two workers. The 

 experiment should be repeated, the temperature of the milk within 

 the receptacle being accurately determined. Uhlenhuth (6, xn. 1902) 

 obtained reactions when antiserum was added to milk which had been 

 boiled, and even with milk which had been exposed to a temperature 

 of 114 C C. for 30 minutes in an autoclave. 



Lactosera do not act on milk only, for Halban and Landsteiner 

 (25, III. 1902, p. 475), following Hamburger, found that human lacto- 

 serum acted also upon human blood serum. They also found that 

 human haematoserum precipitated human milk, just as Schlitze (2, xn. 

 1901, cited in this author's paper of 6, xi. 1902, p. 805) had found 

 antiserum for ox blood to also precipitate cow's milk. 



Meyer and Aschoif (7, vii. 1902) found ox lactoserum to be haemo- 

 lytic for ox blood corpuscles, and that it immobilized ox spermatozoa. 

 The milk which they injected into their rabbits had been previously 

 centrifugalized to rid it of cellular elements which of themselves might 

 have led to the formation of cytolysins. They also found lactoserum 

 to precipitate ox serum. Injections of blood, spermatozoa, and tracheal 

 epithelium, led to the formation of antisera which also precipitated 1 : 40 

 milk dilutions. They found that lactosera (which were also haemolytic) 

 could be neutralized by homologous blood corpuscles or spermatozoa. 



Schiitze (6, XI. 1902, p. 804) found human lactoserum to pre- 

 cipitate solutions of human spermatozoa, and von Dungern (1899 

 1900 Miinchener med. Wochenschr.) found lactosera to agglutinate red 

 blood corpuscles. (See further Hamburger and others, under the Action 

 of Precipitins upon different Albumins of the same animal, p. 104.) 



Uhlenhuth (6, XII. 1902) found lactoserum for cows' milk to produce 

 clouding in ox blood dilutions. He cites an observation of von Dungern 

 to the effect that lactoserum for human milk exerts a toxic action on 

 human milk-gland epithelium. 



Although perhaps not identical with the haematosera, the lactosera 



