Y.I TURE OF THE PROTECTIVE DEFEXCES OF THE BODY 169 



. One objection against the Weigert-Ehrlich hypothesis of overproduc- 

 tion of antitoxin by the specifically attacked cells is that while the 

 animals are still showing tetanic symptoms the receptors of the still 

 diseased cells are supposed to have been reproduced, as shown by anti- 

 toxin production. This is answered by Weigert that while the more 

 important cell atom groups are still suffering, the groups producing 

 the receptors may have recovered. This supposition is difficult to 

 prove or disprove. 



The idea of Weigert, that the cells are biologically altered so as to 

 continue to make receptors (antitoxin) after the cessation of the injec- 

 tions, is not in accord with the observations made by us, as there is 

 uniformly a great drop in antitoxin ten days or two weeks after the 

 cessation of the fresh stimulus of renewed injections. We have also 

 shown that by partially neutralizing toxin before injecting it into ani- 

 mals, it is possible to excite the cells to produce as much antitoxin from 

 the first as from any later injections. 



We know from the researches of Meyer and Ransom that tetanus 

 poison is not absorbed by the affected nerve cells by way of the blood 

 and lymph channels, but reaches them by way of the nerves. Following 

 its injection the tetanus poison ascends in the axis cylinder of the nerves 

 to the motor cells. The tetanus antitoxin, unlike the toxin, is not a 

 neurotrophic substance, but always follows the blood and lymph chan- 

 nels. In adrenalin we possess a substance which is able strongly to 

 contract the capillaries and thus to block the blood absorption path of 

 a particular area. Proceeding from these facts, Wassermann and Bruck 

 devised the following experiment: Tetanus toxin and antitoxin were 

 mixed in such proportions that the mixture was entirely innocuous 

 to animals. If this mixture was injected into the hind paw of a 

 guinea-pig no tetanus developed. When, however, some adrenalin was 

 injected into the hind paw of a similar-sized guinea-pig, and after 

 waiting a few minutes until the capillaries had contracted, there was 

 injected a recent mixture of tetanus toxin and antitoxin, typical tetanus 

 was produced. W T hat happened was this : that the channel of absorption 

 for the tetanus antitoxin had been blocked, while that for the toxin, the 

 nerve path, was open. The toxin had therefore torn loose from its 

 combination and followed its course to the central nervous system, 

 where it produced tetanus. 



This experiment, however, succeeds only within a certain period 

 i. e., not over an hour after mixing the toxin and antitoxin. If we wait 

 a longer time, say, three or four hours, it will be found that even in the 

 adrenalin animal no tetanus is produced, because by this time the com- 

 bination, previously a loose one, is so firm that the substances can no 

 longer be torn apart. This union can be hastened by employing more 

 tetanus antitoxin, for with an excess of antitoxin even after only half 

 an hour it is impossible by means of adrenalin to loosen the tetanus 

 toxin. This experiment, therefore, shows that the tetanus toxin-anti- 

 toxin combination is at first a loose one, and that the affinity becomes 

 firmer and firmer with time. It also shows the possibility of slightly 



