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Preliminary Report upon the Injection of Rabbits with Protein- 

 free (Tuberculo-) Antigen and Antigen- Serum Mixtures. 

 By Alfred H. Caulfeild, M.B. 



(Communicated by Prof. T. G. Brodie, F.R.S. Beceived August 24, — 

 Bead November 2, 1911.) 



(From the Pathological Department of the National Sanatorium Association, 

 Gravenhurst, Canada.) 



The injection of animals and the further study of the resulting serological 

 reactions have mainly been made with proteins, and one has tacitly accepted 

 the L view that the various phenomena were concerned chiefly with this class 

 of antigen. Previous work had shown that the injection of dogs with 

 Vaughn's non-toxic tubercle residue, which is rich in proteins, produced 

 fixation bodies (sensitisers, amboceptors) to an alcohol-ether extract of 

 tubercle bacilli prepared as described.* Following this it was shown that 

 the injection of thisf protein- free extract produced the same result, i.e. 

 specific sensitisers. A determination of other biological reactions is in 

 progress, and will be reported in connection with other parts of the work. 

 At present it can be stated that this serum usually is capable of 

 precipitating certain of the tuberculous proteins. 



The value of the experimental production and study of various biological 

 reactions in animals is obvious, but it has become almost essential for the 

 logical advancement of the investigation begun on patients. From the data 

 obtained in this manner many considerations suggest that the elective 

 material for correlation of the various immunological states is often to be 

 obtained with clinical normals under exposure and cases of early and slight 

 involvements. With the latter, initial implantations can probably only be 

 obtained in children. It is further desirable that the tuberculous infection 

 be the predominant factor,} and not, as often one is forced to conceive, the 

 apex of other pathologic conditions. Obviously the assemblage of such 



* See preceding paper. 



t From the method of preparation a few bacilli may be present in the extract. The 

 extent to which this condition may obtain can be shown to have no practical effect. 



J In this connection, D. V. Hansemann ('Berl. Klin. Wochenschr.,' 1911, vol. 48, No. 1) 

 states that it is not logical to say that the tubercle bacillus is the cause of pulmonary 

 phthisis, as this applies to non-phthisical tuberculosis, notably miliary tuberculosis and 

 acute caseating bronchitis. As regards true tuberculous phthisis, it can only be said that 

 the tubercle is one of the letiologieal factors which is certainly essential for the setting up 

 of the typical caseous process, but which is not capable alone of causing phthisis. 



