[NicHOLLs] BLOOD SERA IN TUBERCULOUS INFECTION 7 



toxins the substance of the germs has been employed as well, but even 

 in this case there is some discrepancy between the different observers. 

 In fact Maragliano is the only one who seems to be at all sanguine as to 

 the value of his serum. 



The few observations I have made have been carried out on slight- 

 ly different lines from those hitherto published in the hope that they 

 would throw some light on a somewhat doubtful question and possibly 

 elicit some new facts. I have employed goats' for the purpose, finding 

 them on the whole the most suitable. It used to be thought that goats 

 were absolutely refractory to tuberculosis but this is certainly not the 

 case. (See Colin. Compt. rend. Acad, de Se, Paris, 1891, CXIII, 

 219). It is true, however, that in a natural state they rarely suffer from 

 the disease. It is, however, possible to give them the disease by inject- 

 ing living virulent bacilli in considerable quantities into the circula- 

 tion, although subcutaneous injection will not sufiSce. They are there- 

 fore relatively immune. Being also hardy animals they stand the various 

 manipulations well. A considerable quantity of serum can be obtained 

 from them which is of good quality and keeps well. Goat serum has 

 the further advantage, as Lépine has shown (Sém. méd. 1891, XI., 21), 

 that it produces much less haemolysis when added to human blood than 

 does dog^s serum. In spite of many advantages goats have not been 

 used to any great extent in this kind of work. Bertin and Picq, Boinet 

 and Niemann are the most noteworthy of those who have done so and 

 report good results. Bertin and Picq (6) found that rabbits previous- 

 ly injected with goat's blood were able to resist a subsequent infection 

 with tuberculosis, although they state that the injections had no effect 

 in animals already tuberculized. 



The Effects of Normal Goat Serum, 



It is now a well recognized fact that the sera of several normal ani- 

 mals possess what may be termed natural antitoxic bodies, or perhaps 

 more correctly alexins. Thus, horse serum possesses about two or three 

 hundred antitoxic units against the diphtheria germ, and according to 

 Maragliano human serum possesses three to four hundred units against 

 the bacillus of tuberculosis. It was thought advisable, therefore, to de- 

 termine first whether normal goat serum could in any sense be considered 

 protective against tuberculosis. Should this prove to be the case, one 

 might then try to increase this up to a practical point. 



For the purposes of the experiment it was obviously necessary to 

 obtain the serum without contamination from bacteria and as nearly 

 normal as possible. To attain this the following method was adopted. 

 A large healthy male goat was taken, the hair was removed over the 

 course of the external Jugular vein in the neck, and the skin washed and 

 sterilized by means of a solution of sublimate (1 — 1000). A large 



