THE AGGLUTININS. 157 



may be inferred from these reactions that agglutinin is one of the 

 globulins or albumins existing in the blood. However, this conclu- 

 sion does not necessarily follow. It is altogether within the range 

 of possibility that the agglutinin is carried down mechanically, as 

 happens to certain ferments and toxins when albuminous solutions 

 are treated with neutral salts. The fact that the agglutinating action 

 has been secured with urine in which no albumin or globulin could 

 be detected, has led some to believe that the agglutinins belong to 

 neither of these bodies. This conclusion also is unjustifiable. 

 Because we cannot detect a globulin or an albumin in the urine is 

 no positive proof that one or both of these substances may not be 

 present. It simply means that neither is present in sufficient quan- 

 tity to respond to the test employed. It must follow therefore that 

 we are not yet in a position to determine whether or not the agglu- 

 tinins belong to the proteid constituents of blood serum. 



A highly active serum after having been diluted with water until 

 no test for proteids' in it can be obtained may still manifest its ag^ 

 glutinating action, while, on the other hand, a serum possessed of 

 but little activity loses its agglutinating property on dilution long 

 before positive tests for the presence of proteids fail. 



Precipitation of typhoid serum with absolute alcohol destroys the 

 agglutinin. This is probably due to the dehydrating action of alco- 

 hol, because if as soon a& the precipitate is formed it be collected on 

 a filter, and the alcohol allowed to drain awa;y and the precipitate ex- 

 tracted with physiological salt solution, this extract will be found to 

 be possessed of a certain amount of a^lutinating power, while, on 

 the other hand, if the precipitate be allowed to remain for some 

 hours under the aloohol, the agglutioini is wholly destroyed. 



The agglutinating action of a blood plasma obtained by the addi- 

 tion of oxalsite of potassium to the blood is more marked than that 

 of the serum of the same blbod. It folfows from this that the ag- 

 glutinin must be in parti retained in the blood clot. Indeed, this 

 can be positively demonstrated by testing the agglutinating action of 

 an extract of the clot made with physiological salt solution. Widal 

 and Sioard have shown quite positively that the white blttod corpus- 

 cles', outside of the' body at le£et, do not furnish the agglutinins. The 

 experiment by means of which this demonstration was accomplished 

 may be briefly described as follows : A sterilized collodion tube was 

 filled with typhoid bteod, to which oxalate of potassiiiin had been 

 added, and allowed to stand. The red corpuscles soon formed a de- 

 posit at the bottom of the tube, and these were covered by a thin coat 

 of white corpusclies, and afetjve these stood the plasma. The plasma 

 was removed with a pipette as thoroughly as possible without taking 

 up any of the leucocytes. Kext the tube was constricted by a string 

 tied around it on a line between the layers of white and red corpus- 

 cles. After these portions had stood for twenty-four hours the rela- 



