24 
One of us (Anderson),® 1907, found that when tetanus toxine is 
exposed to 5 per cent formahn for six hours a guinea pig is able to 
withstand 100 ^ILD of this forinalinized toxine. Three per cent for- 
malin after twenty-four hours’ exposure protects against the toxine; 
it destroys a part of the toxine in one hour, its action increasing with 
the length of exposure. 
THE TETANUS TOXINE. 
On account of its virulence, its solubility, and the characteristic 
contractions which it induces the poison of tetanus has been a con- 
venient and favorite subject of investigation. It was the first of the 
bacterial toxines to give fruitful results in the realm of serum therapy. 
Tetanus toxine is readily soluble in the medium in which the culture 
grows whether fluid or solid. We shall presently see that the filtered 
culture, called the ^Aetanus toxine,” is really a complex substance, 
containing various poisons and other bodies. 
The particular poison that concerns us especially is the tetano-s pas- 
mine, which produces the convulsions characteristic of the disease. 
This poison is a type of a true toxine. It is readily rendered inert by 
heat, contains both a toxophore and a haptophore group, induces 
antibodies when introduced into susceptible organisms, and produces 
symptoms only after a definite period of incubation. Its poisonous 
action is destroyed by the digestive juices. In all these character- 
istics tetanus toxine resembles diphtheria toxine. It is one of the most 
poisonous substances known. As small an amount as 0.000,006 
gram of our standard precipitated toxine invariably kills a guinea pig 
weighing 350 grams. As the precipitate consists mostly of albumins, 
peptone, amido acids, volatile substances, ammonium sulphate, and 
other salts it will be seen that but a small proportion of the weight 
consists of pure poison. Our standard toxine is by no means as strong 
as other tetanus poisons that have been prepared. 
Brieger and Cohn ^ found their strongest tetanus poison killed 
mice vreighing 15 grams when given subcutaneously in doses of 
0.000,000,05 gram; smaller doses, such as 0.000,000,01 gram, caused 
more or less tetanic symptoms in mice. If 0.000,000,05 gram kills 
a mouse weighing 15 grams Brieger and Cohn calculate that 0.000,23 
^ gram would be a fatal dose for a man weighing 70 kilograms. 
Tetanus toxine is not equally toxic for all species of animals. On 
the other hand, there is an extraordinary^ constancy in its toxicity 
o Anderson, John F.; The antiseptic and germicidal properties of solutions of for- 
maldehyde and its action upon toxines. Hyg. Lab. Bull. No. 39, U. S. Pub. Health 
and Mar. Hosp. Serv., Wash., 1907, pp. 47. 8°. 
^ Brieger, Ludwig, and Cohn, Georg; Untersuchungen das Tetanusgift. Zeit. f. 
Hyg., vol. 15, 1893, pp. 1-10. 
