EESEAncn TX SCIENCE 



555 



I'ciiKiins ill (uir ihiiikiiiL;' that whicli 

 brinjis tlic ciiidl ituial a|i|i('al nl' t'pio 

 verse: for licrc, iiidi'cd, men do con- 

 tend with liods and strive to wrest from 

 them tile knowledii'o whieli shall make 

 our future more secure. 



The history of almost any line of 

 scientific investigation, if traced back, 

 will afford illustration of tJK^ matter in 

 hand. The followinu- tliree eases wliicli 

 I have chosen are n>presentative and 

 have often been used in my teaching: 



1 — Microscopic organisms, whieli 

 liave been a subject of careful investi- 

 gation for several centuries. 



•-i^The development of the fresh- 

 water mussel (a case where I can lay 

 claim to some first-hand knowledge). 



3— The study of heredity, a field of 

 investigation which is still in its in- 

 fancy. 



Knowledge of the Microorganisms of 

 Human Disease Began in Theoreti- 

 cal Non-utilitarian Research 



Our present knowledge regarding the 

 microscopic organisms which are the 

 cause of disease is recognized today as 

 of life and death importance for the 

 whole civilized world. But this knowl- 

 edge had its beginning in investigations 

 which w^ere of questionable value when 

 Judged by the utilitarian standards of 

 the past. Society might well profit by 

 this bit of history and assume a far- 

 sighted policy in dealing with scientific 

 investigation in the present. 



That many diseases are caused by 

 minute organisms, living as parasites 

 within the bodies of animals and plants 

 and so producing the derangements 

 called disease, is a fact made familiar to 

 the public during recent years ; and we 

 are making such progress in the discov- 

 ery of germs hitherto unknown, of anti- 

 to.xins, of vaccines, and the like, that 

 even the antivivisectionists may some 

 day be converted. Today, diphtheria is 

 no longer the dangerous and often fatal 

 disease it was even twenty years ago; 

 and if we take the precautions already 



well tested, tliere is no danger that yel- 

 h)w fever will again scourge our Gulf 

 cities, or hiilMiiiic plague devastate Eu- 

 ro|ie and .\inerica as it still devastates 

 the Orient. W'v have conquered typhoid 

 fever, at least in cases of local epidemics 

 or where large bodies of men are sent 

 into dangerous territory, and no man 

 can foresee where our conli'o] of dis- 

 ease will end. 



][a\-e you ever considered how we 

 have attained to this mastery over dis- 

 ease ? Do you know what is the history 

 of tliis knowledge we now have, and 

 whence came this body of facts which 

 now grips us even unto matters of life 

 and death ? I do not refer to the most 

 recent chapters, as heralded in the 

 newspapers or current magazines, when 

 an antitoxin for diphtheria or a 

 method of preventing typhoid fever has 

 been announced. These are but the 

 recent pages of a book long in the mak- 

 ing, to find the title-page of which we 

 must turn back through many years 

 and to matters having little apparent 

 connection with what is now before us. 



To test the truth of this last state- 

 ment, let us trace the course of man's 

 discoveries regarding the microorgan- 

 isms, taking as a convenient starting 

 point the year 1676 when the Hollander, 

 Antony van Leeuwenhoek, discovered 

 with the microscope, which had but 

 lately come into use as a toy and source 

 of amusement, what he described as 

 ^'little animals observed in Eain, Well, 

 Sea, and Snow Water as also in Water 

 wherein Pepper had lain infused.*" ^ 

 Leeuwenhoek's discoveries were, I sup- 

 pose, regarded as useless by all his con- 

 temporaries save a few, by whom the 

 work was highly esteemed. Some small 

 means enabled him to devote a generous 

 part of his time to study; and at the 

 end of a long life he had examined with 

 his microscope pretty much everything 

 he could lay hands upon in both ani- 



^ S(>e Kont, AV. Saville, Manual of the Infusoria, 

 for quotations from, and an account of, the work of 

 Leeuwenhoek. 



