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Anglo-Saxon civilisation to progress in 

 places where even six years back a new- 

 comer could count his reasonable expecta- 

 tion of life on the fingers of one hand. 

 Tropical medicine has assumed such 

 great proportions that it practically forms 

 the pivot upon which turns the whole 

 guestion of European colooisation in the 

 tropics, and, practically speaking, tropical 

 medicine is very largely based upon the 

 spread of disease by insects. There, free- 

 dom from malaria practically means 

 freedom from ill-health. The London and 

 Liverpool schools have received noble 

 recognition from Mr Chamberlain, and 

 from hard-headed business men who can 

 see into the future. Many a Peter the 

 Hermit is leading a crusade against dis- 

 ease with knowledge, and often with funds 

 supplied in this way, enabling the British 

 race to get on a step further with colonisa- 

 tion. America has taken up the work 

 with especially striking results in relation 

 to Yellow fever, and a handful of workers 

 succeeded in clearing Havana of this fell 

 disease in ninety days — after it had had 

 an uninterrupted reign for 140 years. 

 The discoveries which have been made 

 are, I think, but a foretaste of those which 

 are to come, but their histories, with the 

 patient record of constant toil over minute 

 details, of the sacrifice of leisure and re- 

 creation, and even in some cases of the 

 iives of the workers for the furtherment of 

 knowledge^ form, to my mind, one of the 

 6<)bl3st romances ever written. The work 

 of Manson, Eoss, McCallum, Reid, and 

 others have revolutionised the methods 

 of research into human disease, and there 

 is little doubt that we are on the verge of 

 further great discoveries in which the 

 lower forms of life will be found to play 

 an essential part in disease affecting man- 

 kind. But this may appear to be some- 

 thing of a digression from the practical 

 treatment of my subject. I trust, how- 

 ever, that I have shown you to some 

 small extent the importance of the results 

 obtained, and the possibilities which they 

 open up. I will now endeavor, with the 

 aid of a few lantern slides, to indicate in 

 some measure the manner in which these 

 discoveries have been made, the difficul"- 

 ties against which the workers had to 

 contend, and the method in which they 

 are practically' applied. 



The classical example is, of course, sup- 

 plied by malaria, or paludism, as it is often 



termed. As I need hardly point out, both 

 these terms indicate the association with 

 the presence of marshes, swamps, and 

 other wet-soiled localities, which has been 

 for centuries noted in connection with the 

 disease, malaria meaning merely "bad 

 air," and paludism the condition induced 

 by marshes. Now, about the middle of 

 last century, certain observers noted the 

 presence of certain brown and black 

 granules in great numbers in the blood 

 and organs of malarial patients, and 

 in 1880, . Dr, Laveran, a French 

 military isurgeoh in Algeria, made the 

 discovery that the black granules, which 

 are known as melanin, were produced by 

 the action of immense numbers of tiny 

 parasites living in the red blood cor- 

 puscles. This was a very notable dis- 

 covery, as it naturally caused enquiry 

 into the manner in which the parasites 

 got into the blood corpuscles, and once 

 there how they produced the fever. 

 It was found that they could not be 

 grown on artificial media, even from 

 blood which swarmed with them, and 

 other discoveries soon made it clear that 

 they represented a distinct form of 

 animal life, and not a vegetable one, like 

 the bacteria ■ for instance. Some five 

 years later another discovery was made, 

 namely, that these parasites breed in the 

 blood, and that the attacks of fever coin- 

 cide with the breaking up of the cluster of 

 spores so formed. It was also found 

 that three varieties at least of the or- 

 ganisms infect men, and that yet others 

 were to be obtained from the blood of 

 birds, bats, cattle, monkeys, and other 

 animals. 



(A picture .was then shown of one form 

 of malarial organism as it appears under 

 the microscope in the various stages of 

 development, which are traceable in the 

 blood so long as it retains its vitality after 

 removal.) 



Under the microscope, the strange 

 octopus-like creature, which represents 

 the last stage of development in blood 

 specimens, would attract your attention 

 even more than in the lantern pictures, 

 since its arms are in vigorous motion 

 from the time they shoot out from the 

 surface. If kept moist and warm another 

 strange phenomenon occurs. One or 

 more of these arms will be seen to sepa* 



