Albuminnria in Rabbits 133 



although no precipitins were formed in this animal. M. Ascoli (1903) 

 has in a similar manner been able to demonstrate the presence of 

 egg-white, and of substances derived from roast fowl in the lymph 

 of dogs fed therewith. He was unable to note a parallelism between 

 the amount of precipitable substance contained in the dog's lymph 

 and blood serum. The serum of human subjects fed on roast beef also 

 contained substances which were precipitated by an homologous anti- 

 serum for ox meat. Where precipitins were contained in the serum 

 of an animal thus fed, the amount of precipitin therein underwent 

 considerable oscillations when a corresponding food was given. The 

 experiments will be reported upon in extenso in a future paper. 



The presence of albuminuria in rabbits treated with foreign albumin 

 is noted by Hamburger (6, xi. 1902). This is however an old observa- 

 tion, which has been made not only on animals but also on man, by 

 physiologists and others, in connection with the so-called physiological 

 albuminuria as the result of food rich in albumin. Hamburger, however, 

 has made very important observations with respect to the albuminuria 

 which is observed in the course of immunization with egg-white. He 

 found that the albuminuria disappeared during the process of successful 

 immunization. Moreover the earlier the albaminuria disappeared, the 

 sooner did the animal form a powerful antiserum. 



In a rabbit in which the albuminuria disappeared after the third 

 injection of egg-white, an antiserum was obtained which reacted with 

 egg-white dilution of 1 : 200,000, whereas in the case of another rabbit 

 in which the albuminuria only disappeared after the sixth injection, 

 the antiserum only reacted with an egg-white dilution of 1 : 40,000. 

 The practical bearing of this observation is clear for those engaged 

 in the preparation of precipitating antisera, and without doubt Ham- 

 burger's discovery is of general interest, not only from its physiological 

 aspect, but also from the standpoint of immunity. The degree of 

 albuminuria may very well serve as a guide as to the grading of dosage 

 during such immunizations. And I do not doubt but that the method 

 would prove the need of grading the dosage much more carefully than 

 some observers have done. Some indeed have made no attempt at 

 gradation, but have injected 10 c.c. for example of a foreign serum, 

 I might say blindly, every time, during the whole course of treatment. 



That the albuminuria in rabbits is not simply due to an escape 

 of egg-white, was proved by Hamburger through the use of two antisera, 

 anti-rabbit and anti-egg sera. These antisera gave reactions with both 

 albumins, when the coarser tests of boiling and nitric acid ceased 



