April 24, 1908] 



SCIENCE 



645 



this term and hope that some one will sug- 

 gest a better. 



I desire it plainly understood that in 

 what I am to say to-day about hypersus- 

 ceptibility and immunity I am speaking ex- 

 clusively of what I have designated as 

 "lytic immunity." The following state- 

 ments are based largely upon work done in 

 my own laboratory and I will condense as 

 much as possible ; and in doing so my state- 

 ments may seem dogmatic, for I can not 

 take the time to prove each of them, but 

 such proof may be found in the papers 

 that have been published by my students 

 and myself. 



All true proteids contain a poisonous 

 and a non-poisonous gi'oup and can be 

 split into these groups by the action of 

 dilute alkali in absolute alcohol at 78°. 

 The presence of the amino-acid tyrosin is 

 apparently essential to the poisonous group, 

 and those albuminoids, such as gelatine, 

 that do not contain tyrosin yield no poison- 

 ous group. So far we have tested more 

 than twenty different proteids, bacterial, 

 vegetable and animal, and all that contain 

 the tyrosin group yield a poison. Please 

 understand that I do not claim that tjrrosin 

 is the poisonous group, but I believe it to 

 be a constituent of the poisonous body. 

 The poison does not contain a carbohydrate 

 or a nuclein group, the absence of the latter 

 being demonstrated by the complete ab- 

 sence of phosphorus. The non-poisonous 

 group consists largely of nuclein, the car- 

 bohydrate being a sub-group in the nucleic- 

 acid molecule. 



The poisons obtained from these dif- 

 ferent proteids, although not identical, are 

 similar and probably owe their poisonous 

 action to the same or similar atomic ar- 

 rangement. Much of the poison is de- 

 stroyed by our crude method of obtaining 

 it. The effect of the poison on animals is 

 characteristic or pathognomonic and mani- 



fests itself in three stages. The first is a 

 period of peripheral irritation manifesting 

 itself in animals by violent scratching and 

 in man by itching, erythema or urticaria. 

 The second may be designated as the period 

 of depression with or without partial 

 paralysis. The third or convulsive stage is 

 characterized by more or less violent clonic 

 convulsions, generally beginning with opis- 

 thotonos and terminating in death. These 

 symptoms are identical both in character 

 and in sequence whether induced in a fresh 

 animal by the injection of the free poison 

 or in a sensitized animal treated with the 

 unbroken proteid. When a non-lethal dose 

 of the free poison is given, the first and 

 second stages only appear, and the same is 

 true when a non-lethal dose of the un- 

 broken proteid is administered to a sensi- 

 tized animal. The proteid contains the 

 poison, which can be extracted by chemical 

 means. The free poison and the unbroken 

 proteid in appropriate animals induce the 

 same sjonptoms, in the same sequence and in 

 the same time. There is therefore no more 

 doubt that the animal that dies from the 

 free poison and the one that dies from the 

 unbroken proteid die from the same poison 

 than there is that the man who dies from 

 morphine and the one who dies from opium 

 die from the same poison. The poisonous 

 portions of these proteids produce no anti- 

 bodies when repeatedly injected into ani- 

 mals, and only slightly increase the toler- 

 ance for themselves. Likewise they slight- 

 ly increase tolerance for the unbroken pro- 

 teid in sensitized animals. Even in this, 

 however, their action is not specific. It 

 seems evident from these findings that the 

 poisonous or the toxophore group in the 

 proteid molecule plays no part in the pro- 

 duction of lytic immunity. In this respect 

 the production of lytic and antitoxic im- 

 munity agree, but in the former there is 

 no antitoxin formed. 



