264 TUBERCULOSIS. 



temperature more than .5 F. Though cases of lupus have 

 been recorded in which improvement has taken place, little 

 success has attended the use of this substance as a remedial 

 agent. 



Immunisation against the Tubercle Bacillus : Anti-tubercular 

 Serum. Tuberculosis differs from other diseases, against which 

 animals can be immunised, in that there is no evidence that one 

 attack protects against a second. Further, we have no means 

 of obtaining truly attenuated tubercle bacilli. Many attempts 

 at immunisation have, however, been made. It has been 

 thought by some that the tubercle bacilli from so-called scrofu- 

 lous glands are less virulent than those say from phthisis, but 

 apparently here sufficient attention has not been paid to the 

 difference of the numbers of bacilli injected in each case, and 

 this appears to be a very important point. Experiments have 

 also been brought forward which appear to show that the injec- 

 tion of bacilli from avian tuberculosis could protect the dog 

 against bacilli derived from man. But these are not yet conclu- 

 sive. Further, many attempts have been made at immunisation 

 against the tubercle bacillus by the employment of its toxic 

 products. The most successful have been those of Maragliano. 

 We have seen that this author distinguishes between the toxic 

 bodies contained in the bodies of the bacilli (which withstand, 

 unchanged, a temperature of 100 C.) and those secreted into 

 the culture fluid (which are destroyed by heat). The substance 

 used by him for immunising his animals consists of three parts 

 of the former and one of the latter. The animals employed are 

 the dog, the ass, the horse. The serum obtained from these is 

 capable of protecting healthy animals against an otherwise fatal 

 dose of tuberculin, but very little importance can be attached to 

 this result. Maragliano does not appear to have studied the 

 effects of this serum on tubercular animals, but it has been tried 

 in a great number of cases of human tuberculosis, 2 c.c. being 

 injected subcutaneously every two days. Improvement is said 

 to have taken place in a certain proportion, especially of mild 

 non-febrile cases. 



Methods of Examination. ( i ) Microscopic Examination. 

 Tuberculosis is one of the comparatively few diseases in which a 

 diagnosis can usually be definitely made by microscopic exami- 

 nation alone. In the case of sputum, one of the yellowish frag- 



