408 Tetanus 



In the first series of tests, the same quantity of the test 

 serum is mixed with quantities of the toxin varying from 

 the point of neutralization (L ) to more than the test dose 

 (L, + ) until the test dose is determined. The second series, 

 by which the strength of the unknown serum is actually deter- 

 mined, is made by mixing with the test dose of toxin varying 

 quantities of the serum according to its supposed value, 

 until the least quantity is determined that will save the 

 white mouse from death from tetanus on the fourth and 

 fifth day. 



The actual test may be carried out as follows * : 



T -IO c.c. of the test toxin contains 40,000 + minimal fatal doses per 

 gram of white mouse. From the serum whose antitoxic value has 

 been proved various dilutions are prepared (1 : 100; 1:95; 1:80, etc.). 

 1 c.c. of each of these is placed in an Erlenmeyer flask together with 

 1 c.c. of the test toxin and 38 c.c. of distilled water. After the mixture 

 has stood one-half hour, each mouse receives 0.4 c.c. under the skin. If 

 the mouse receiving the 1 : 100 dilution dies in four or five days, and the 

 mouse with the 1 : 80 dilution remains well and that with 1 : 90 dilution 

 acquires a slight tetanus, a new dilution 1 : 85 must be made and tested. 

 If the mouse receiving it remains well, the value of the serum may be 



calculated thus: = A. E. 



The white mouse is the animal found best adapted to 

 the test, just as the guinea-pig is for diphtheria tests. The 

 mixtures of toxin and antitoxin are allowed to stand for 

 three-quarters of an hour in the incubator before being 

 injected into the mouse, this being made necessary by the 

 fact that the tetanus toxin has far less avidity for anti- 

 toxin than diphtheria toxin for diphtheria antitoxin. The 

 injections are made into the skin of the back. At the 

 Frankfort-on-the-Main Institute this method of testing is 

 said to be exact within 5 or 6 per cent. 



Numerous cases of the beneficial action of this antitoxin 

 are on record, but, as Welch t has pointed out, the anti- 

 toxin of tetanus has proved a disappointment in the 

 treatment of tetanus. Moschcowitz,{ in his excellent 

 literary review of the subject, has shown that its use has 

 reduced the death-rate from about 80 to 40 per cent., and 

 that it therefore cannot be looked upon as a failure. The 

 result of its experimental injection, in combination with 

 the toxin, into mice, guinea-pigs, rabbits, and other animals 

 is perfectly satisfactory, and affords protection against 



* See v. Lingelsheim's paper in Kolle and Wassermann's "Pathogene 

 Mikroorganisrnen," Bd. iv, Th. 2, p. 989. 



t " Bulletin of the Johns Hopkins Hospital," July and August, 1895. 

 t "Annals of Surgery," 1900, xxxn, 2, pp. 219, 416, and 567. 



