26 ROYAL SOCIETY OF CANADA 



good results as I obtained, for the reason that its aggiuiinative power 

 was-' comparatively low (1 — 50) and it was possible to have increased 

 this enormously. Possibly the serum of a goat treated by the tuber- 

 culin to saturation would give still better results. There would, how- 

 ever, be a limit to this procedure for the glycerine in Koch's emulsion 

 would prove toxic when injected in any amount, producing hsemoglo- 

 binuria. Some method would therefore have to be devised whereby all 

 the products of the tubercle bacillus could be injected without any for- 

 eign substances. In my opinion the various antituberculosis sera that 

 have hitherto been produced have very questionable clinical value when 

 applied to human beings. Of course after the announcement of any 

 new curative agent there is always an outcry in its favour, but, in the 

 case of tuberculosis, serum after serum has been placed upon the mar- 

 ket, only to be weighed in the balances and found wanting. The only 

 serum that is still being used is that of Maragliano, and| he is so con- 

 vinced of its utility that an institute has recently been established in 

 Italy for the treatment of tuberculosis by his method, to which he sup- 

 plies serum gratis. The profession, however, appears to be strongly 

 sceptical, for there is no rush to his laboratory from all parts of the 

 world such as there was when Koch's ill-starred tuberculin was first 

 announced. Maragliano's reported results, namely sixty per cent or 

 thereabouts of improvements, are not much in advance of the figures' 

 furnished by any first class sanatorium, such as the Saranac Lake, 

 Loomis, Muskoka, and Gœrbersdorf institutions, which are from forty 

 to sixty per cent of cures in the early stages. It is moreover very difii- 

 cult to, estimate the value of any curative agent in the case of such a 

 variable and insidious disease as tuberculosis. Many cases do well when 

 placed in suitable surroundings with proper care and diet without drugs, 

 and the disease is notoriously liable to unexpected remissions. The 

 results of the serum treatment are not so good that we can yet aban- 

 don the attitude of expectant hope, nor should we pause in our 

 attempts to obtain a still more potent serum. It may indeed well be 

 that we have reached the possible limit of efiicacy in the sera prepared 

 by the methods hitherto adopted, and Koch is quite possibly right 

 when he says that immunity to the action of the toxic products of the 

 tubercle bacillus does not necessarily mean immunity to tuberculosis. 

 We probably need some serum powerful enough to destroy the bacillus 

 in the tissues or which, perhaps, will stimulate the body cells to ela- 

 borate a germicidal substance. The germicidal properties of the sera 

 hitherto prepared do not appear to have been accurately observed and 

 the subject will bear further study. Possibly advances in this direction 

 will have to be made on the lines of Behring's recent work, who has 



