ESSAYS 329 



very much from the immunising and curative value of the vaccine. For thera- 

 peutic purposes, therefore, detoxicated vaccines should prove of the greatest 

 value, because the immunisation of the patient can be attained without appreciably 

 adding to the toxic symptoms resulting from the disease itself. 



The following table shows approximately the comparative dosage of detoxicated 

 and ordinary vaccines : 



Germ. Detoxicated Vaccine. Ordinary Toxic Vaccine. 



Gonococcus 2,500,000,000-10,000,000,000 25,000,000-100,000,000 



Meningococcus 2,500,000,000-10,000,000,000 (?) 



Staphylococcus 10,000,000,000 250,000,000-1,000,000,000 



Influenza bacillus 500,000,000-1,000,000,000 50,000,000-100,000,000 



Pneumococcus 2,500,000,000-10,000,000,000 200,000,000-500,000,000 



Micrococcus \ 



, ,. > 1 ,000,000,000-2,000,000,000 50,000,000-100,000,000 



rxe organisms 1 000000000 _ 2 500,000,000 100,000,000-250,000,000 

 for coryza J ' ' ' '* ' ' ' ' •* ' 5 



Tubercle bacilli 500,000,000-1,000,000,000 (?) 



Researches with detoxicated coryza vaccines in the prevention and treatment 

 of common colds, bronchitis, and so-called influenzal attacks holds out consider- 

 able promise of success. 



There is still, however, another problem of great interest in connexion with 

 the production of immunity by means of specific inoculations. In the course of 

 my investigations on the vaccine treatment of gonorrhoea it was noted that the 

 amount of antisubstance produced in different patients as the result of equal 

 inoculations varied in a very remarkable manner. Thus, while some subjects 

 developed ten units of immunity after the injection of a total of 40,000,000,000 of 

 detoxicated gonococci, others only developed some four or five units even after 

 a total of 80,000,000,000. Those who had the power of developing a large amount 

 of antisubstances got better much more rapidly than those who showed a feeble 

 capacity in this respect. This variation of power in producing antisubstances as 

 the result of inoculations did not appear to me to have any very definite relation- 

 ship to the robustness of the patient. 



It is obviously very important that the cause of this variation in different 

 individuals should be discovered. When we are able to inject large quantities of 

 vaccine, and when, in addition, we know the conditions necessary for a powerful 

 response of antisubstances, then our mastery over bacterial diseases will be to a 

 large extent complete. 



In recent years our knowledge regarding bacterial antibodies has greatly 

 increased, so much so that it is possible to detect them in the blood, and even to 

 measure the amount produced by a given inoculation. With careful quantitative 

 researches, therefore, on these lines there is no reason why highly efficient and 

 successful vaccines should not be obtained for almost all of the infectious diseases. 



DUST INHALATION AND MINER'S PHTHISIS (H. W. Davies, 

 MB., B.S., Captain, Australian A.M.C.) 



Miner's phthisis is a disease which has long been recognised, and in certain 

 localities, notably the Transvaal, is well known on account of its prevalence and 

 deadly character. It is caused by certain dusts, mainly the various forms of pure 

 silica, which accumulate in the lungs, setting up a fibrosis, and rendering them 

 v ery much less resistant to infection by tubercle bacilli. Coal-dust, on the other 



22 



