4 ROYAL SOCIETY OF CANADA 



«nd actinomycosis also belong, that have a notably slow progression, pre- 

 senting, it is true, eil'ects referable to a mild intoxication, but also char- 

 acterized by the production of gross organic lesions (granulomata) in 

 various parts. Here it is obvious that a purely antitoxic serum, that is 

 to say, one that merely neutralizes the poisons elaborated by the tubercle 

 bacillus m the course of its growth, is hardly likely to prove effective. 

 Should it be possible to prepare such a serum, and, as we shall see, it 

 undoubtedly is, the disease would still progress. To be of real value a 

 serum would apparently need to possess germicidal as well as antitoxic 

 properties. Even in the days of the discovery of the diphtheria 

 antitoxin and before (1884), attempts were made to solve the problem 

 and the names of Héricourt and Richet stand out as pioneers in this 

 line of research.' Since then the number of workers has increased mar- 

 vellously, and the work of Koch, Maragliano, Babes, Mafïuci and Di 

 Vestea, Behring, Niemann, and on this continent, Trudeau, and 

 DeSchweinitz, is a monument of painstaking re'search, scientific accur- 

 acy, and devotion to truth. Ko one who has not investigated the sub- 

 ject would credit the enormous amount of labour expended on this one 

 problem. A glance at the bibliography appended to this paper, which 

 represents merely one phase of the subject, namely that relating to 

 animal sera, will emphasize the truth of this remark. 



The subject has been attacked in various ways. One class of inves- 

 tigator has attempted the cure of tuberculosis by means of drugs, a 

 mode which seems again of late to be coming into prominence. A sec- 

 ond school, of which Koch has for some years been the leading spirit, 

 has sought to produce immunity and cure the disease by the injection 

 of various toxins derived from the tubercle bacillus or chemical modi- 

 fications thereof. To this category of remedies b'^long the various tuber- 

 cnlins,oxy tuberculin, tuberculocidin, and antiphthisin. By the injection 

 of these snbstances it is sought to stimulate the cells of the body to the 

 elaboration of an antitoxic substance in such amount as to neutralize 

 the poisons eliminated by the bacilli. The third series of experimenters 

 has endeavored by the injection of various extracts of tubercle bacilli 

 or in some cases the living attenuated germs, to produce immunity in 

 certain of the lower animals, and then to use the blood serum of ani- 

 mals thus fortified to combat the disease in other individuals. It is 

 with work of this last class that this paper alone will deal. 



The first observation, and one that has led to all the rest, was that 

 of Héricourt and Richet. In 1888 they noted that if a rabbit, which is 

 very susceptible to this germ, be inoculated with the staphylococcus 

 pyosepticus, it may be rendered refractory to its action by intraperi- 

 Toneal injection of dog's blood, an animal that possesses a natural immu- 

 nity to the infection. This suggested to their minds that the same 



