Page:The Harveian oration 1888.djvu/40

32 of cod-liver oil is of great service generally in the treatment of Phthisis few I think will deny, and the same may be said of the free use of butter as an article of diet; the latter sometimes even appears to answer better than the cod oil, and is certainly more willingly taken. But what possible effect can oil and butter have on bacilli? Indeed I fear that the discovery of the tubercle bacillus has not proved in some respects to be an unmixed benefit, and that the result of treating patients in various ways by antiseptic remedies, has been that the patient, and not the bacillus, has succumbed.

Lastly, there is one important point to refer to in connection with these micro-organisms. We are surrounded on all sides with certain forms of them which under ordinary circumstances produce no injurious effects on the human frame, living only as saprophytes on dead animal or vegetable matter. Can these harmless organisms under any mode of cultivation acquire virulent or poisonous properties enabling them to attack living animal matter? Can the common bacillus of hay infusion, the bacillus subtilis be transformed into the bacillus anthracis? Or putting the question more generally can a specific disease arise de novo? Pathologists and bacteriologists differ strongly on this point. Buchner says that the transmutation of the hay bacillus into the bacillus anthracis does take place. Koch and Klein say it is impossible. All admit that the bacillus anthracis, if cultivated outside the human body, artificially, at a certain temperature, can have its properties so modified that it ceases to be poisonous, and after six weeks' attenuation can be injected into the blood of a living animal without producing any injurious effects : rabbits resist the injurious effects at an early stage of attenuation, guinea-pigs at a later stage, while it is only after the parasite has been cultivated