116 THE SPECIFIC PBECIPITINS. 



sheep, since, as the following experiment shows, immunization against 

 sheep's globulin leads to the appearance in the serum of two distinct 

 agglutinins, for sheep's and for fowl's corpuscles, respectively. It 

 the serum of a rabbit immunized against sheep's globulin be allowed 

 to agglutinate washed corpuscles of the sheep, the clear fluid left 

 above the corpuscles will not now agglutinate fresh corpuscles of the 

 sheep if sufficient corpuscles have been used in the first instance. 

 But this fluid still has the power of agglutinating fowl's corpuscles. 

 And, conversely, after antiglobulin has agglutinated fowl's cor- 

 puscles, it has lost the power of agglutinating fresh fowl's cor- 

 puscles, but will still agglutinate those of the sheep." Animals 

 immunized with pepton furnished a serum which gave a precipitum 

 with pepton and failed to react with any other proteid. The pepton 

 precipitum, after being carefully washed with physiological salt so- 

 lution and then dissolved in two per cent, saline solution, does not 

 give the biuret test. Myers attempted to determine whether or not 

 the precipitin is used up in the formation of the precipitum and on 

 this point he makes the following statement : " A mixture of the 

 precipitins of bullock's globulin and egg albumin was added to a so- 

 lution of egg albumin. After standing at 37° for fifteen hours the 

 mixture was centrifugalized and the clear fluid was tested for the 

 presence of the precipitins. It was found to give a precipitum with 

 bullock's globulin but to give none with egg albumin. At the same 

 time a control experiment was made with a mixture of the precipi- 

 tins of egg albumin and bullock's globulin with bullock's globulin. 

 In this case the clear fluid precipitated with egg albumin but not 

 with bullock's globulin. Experiments of a similar kind with the 

 precipitins of egg albumin and sheep's globulin were made, and in 

 this case also the one or other of the precipitins disappeared. From 

 these experiments it is concluded that the precipitins are used up in 

 the course of their action, and bearing in mind their specificity, this 

 is strong evidence that the action of these bodies is chemical." 



Uhlenhuth ' broke freshly laid eggs in sterilized beakers, diluted 

 with physiological salt solution, stirred with sterilized rods, and thus 

 prepared a solution which could be easily injected intra-peritoneally 

 into rabbits. In this way he introduced into each animal at each 

 time the whites of from two to three eggs, and notwithstanding the 

 large volume of the fluid, which frequently measured 100 c.c, it was 

 well borne. After this operation had been repeated several times 

 the rabbits furnished ovasera which proved to be most delicate re- 

 agents in testing for egg albumin, inasmuch as a few drops of such a 

 serum added to egg albumin diluted with one hundred thousand parts 

 of water, give a distinct cloudiness, while nitric acid and acetic acid 

 and ferrocyanide of potassium fail to indicate the presence of albumin 

 when the solution is diluted only 1:1000. Moreover, this reaction 

 iDetttscAe med. Wochmschrifl, 1900. 



