496 INFECTION AND RESISTANCE 



after treatment and their rapid disappearance after the inciting 

 stimulus is removed. Thus Abderhalden reports that the enzymes 

 found in a case of pregnancy disappeared within eight days after 

 abortion or child birth. 



It is plain that these researches of Abderhalden offer many op- 

 portunities for diagnostic utilization, and he has applied them to the 

 diagnosis of pregnancy. In this condition substances from the 

 chorionic villi get into the blood. These, according to Abderhalden, 

 may be looked upon as in a certain sense foreign in nature, and must 

 be chemically disintegrated by the body. In consequence it is likely 

 that the ferments which accomplish this would appear in the sera of 

 pregnant individuals and could be determined by his methods. 

 When he prepared peptone from the placental substances of human 

 beings and allowed the blood plasma of normal individuals to act 

 upon it, observing it both by the dialysis and the optical method, no 

 peptolytic action could be observed. However, when the plasma of 

 pregnant women was used proteolytic action was determined. In 

 these cases the ferment seemed to be specific for peptones produced 

 from placental tissue both in animals and human beings, but did not 

 act upon casein, gelatin, or other proteins. There are certain techni- 

 cal difficulties connected with the production of a test material from 

 the placental tissue which render this method difficult. For their 

 more detailed description we refer the reader to the original articles. 

 Abderhalden believes that his protective ferments may have consid- 

 erable bearing upon the problems of bacterial immunity and anaphy- 

 laxis, and this of course is evident to every one who has followed 

 the development of these subjects. The problem, however, is a com- 

 plicated one, and it is qute impossible at present to draw definite 

 conclusions. 



THE MEIOSTAGMIN REACTION 



Ascoli and Izar 6 have attempted to work out a diagnostic reac- 

 tion which depends upon an alteration of surface tension of a fluid 

 when an antigen unites with its specific antibody. Ascoli in his first 

 experiments worked with typhoid bacillus extracts and the sera of 

 typhoid patients, and found that when the two suspensions were 

 mixed a reduction of surface tension resulted after time for union 

 between the two had been allowed. 



They determined the reduction of surface tension by Traube's 7 

 method by the use of apparatus spoken of as the "stalagmometer." 

 The principle of this method depends upon the fact that as surface 

 tension is reduced the number of drops to a given quantity of fluid 

 is increased. 



6 Ascoli and Izar. Munch, med. Woch., Nos. 2, 7, 18, 22, 41, 1910. 



7 Traube. Pfluger>s Archiv, Vol. 123, 419. 



