nESEAnCH IN SCIENCE 



iiijih' ;iiul iiiiiiiiuiatc nature. Among 

 olluT things lie discovorcd some of the 

 lai\u-er bacteria, many protozoans, the 

 passage of blood from arteries to veins 

 111 rough the capillaries (the one link 

 lu'cdcd to complete Harvey's evidence 

 for the circulation), and he was the 

 first to describe the human s])ermato- 

 zoon. He thus became the lirst gr^'at 

 microsco]iist. 



"We wore dreanicrs, dreaming greatly, 

 in the man-stifled town; 

 We yearned beyond the sky-line where 

 the strange roads go down." 



lX'S])ite crude and iniperlV'ct micro- 

 scopes, knowledge of these animalcules 

 grew a})ace, and during the eighteenth 

 century the more important types were 

 recognized. Their discovery reopened 

 the discussion of spontaneous genera- 

 tion, which, a few years before Leeuwen- 

 hoek's first observations, had been dis- 

 credited in the ease of insects and 

 larger organisms, and a bitter conflict 

 was long waged between the opposing 

 forces. During this struggle facts were 

 established which not only aided in the 

 final triumph of our conception of 

 biogenesis, but also resulted in exten- 

 sions of knowledge useful in other di- 

 rections. 



With the advent of the cell theory in 

 1839 and with marked improvements of 

 the microscope, the distinction between 

 multicellular and unicellular organisms 

 was established, while the age-long 

 controversy was closed by Pasteur in 

 his studies upon disease and fermenta- 

 tion, Tyndall in his examination of the 

 floating matter of the air, Dallinger 

 and Drysdale, who first observed the 

 complete life cycle of a protozoan, and 

 a host of others. And here, these "na- 

 ture searchers," who since the days of 

 Leeuwenhoek had been pressing their 

 forces into the seemingly useless fields 

 which teemed with microscopic life, 

 joined with the men long baffled in 

 their fight for human lives, and gave to 

 medicine tlie support needed in reach- 



ing the vantage ground from which to 

 discover a new horizon line in the 

 "germ theory of disease." 



Foralong time, physicians had known 

 that certain diseases were "catching." 

 "The pestilence that walketh in dark- 

 ness,"" was no idle figure of speech. An 

 analogy between the spread of disease 

 and the spread of living organisms had 

 heeii pointed out for centuries. Pait 

 only in the nineteenth century, in the 

 generations of our fathers and grand- 

 fathers, did the medical men, aided by 

 the investigators who had ventured into 

 tlie wider domain of abstract science, 

 show that the germ is so truly the cause 

 of infectious disease that without the 

 microscopic germ the disease does not 

 exist.i Since the firm establishment of 

 this germ theory, now the "germ fact" 

 of disease, investigations in this direc- 

 tion have received increasing support, 

 until in recent years we have seen the 

 establishment of institutions for gen- 

 eral medical investigation, like the 

 Eockefeller Institute in New York City 

 or the Cancer Laboratory in Buffalo. 

 And so immediate have been the re- 

 sults, we may well believe that labora- 

 tories of this character are destined 

 in the near future to be generously 

 supported by state and private benefi- 

 cence. 



The point for us is that these recent 

 triumphs in an applied science had 

 their beginnings in the days of Leeu- 

 wenhoek, and that this attainment has 

 been possible because of the work of 

 investigators who did not consider the 

 immediate utilitarian values of what 

 they sought, because of the labors of 

 men who persevered in the belief that 

 all facts of nature are worth while and 

 who died in the faith that somehow, 

 sometime, the facts they had estab- 

 lished would find a place in man"s 

 scheme of the universe. 



' First-liand contact with tlie medical discussion 

 of this period may be obtained in Oliver Wendell 

 Holmes's essay upon puerperal fever, written in 

 1843. This is well done and has the advantage 

 of being found in almost every library. 



