The President's Address. By G. S. Woodhead. 117 



microscopic observation is the foundation on which all new 

 knowledge must be built up. The common feature of this as of all 

 other results obtained by honest work in any field of science truly 

 recorded, is that it always remains a coign of vantage from which 

 fresh fields may be surveyed and explored new regions full of 

 beauty and wealth and from these again still greater lands and 

 more beautiful. 



Although van Leeuwenhoek, through his close association with 

 the Koyal Society of London and the French Academy of Sciences, 

 is, very rightly, most closely associated with the development of 

 microscopy in relation to medicine, we have to go back to Athanasius 

 Kircher of Fulda, a Jesuit priest, scholar and microscopist, for the 

 first* of that long series of investigations into the microscopic 

 causes of disease that shed such lustre on the seventeenth century. 

 This work lay dormant for a period and bore little fruit, but it was 

 again brought to light in the latter part of the eighteenth century 

 with results as far reaching and important to men as were those 

 obtained by Galileo (1609), whose "telescope had given a glimpse 

 of the intimate vast in astronomy. "t Although Kircher' s " worms," 

 which he found in decaying matter, were certainly not met with in 

 the blood from plague patients which he examined, it is possible, as 

 Loeffier % points out, that he actually saw some of the larger 

 bacteria met with in decaying matter, working as he did with a 

 magnification of some 32 diameters. However this may be, such 

 magnification and definition as he could obtain were not sufficient 

 to enable him to discriminate between the pus cells or leucocytes 

 and rouleaux of red blood corpuscles and these minute organisms. 

 These observations, however, trained Kircher's mind on the subject 

 of the causation of disease. He was convinced that disease was 

 produced by something that could multiply, something that had the 

 attributes of a living organism, and he stated very definitely his 

 belief in a contagium animatum as to the cause of infective disease. 

 It is interesting to find, as pointed out by Garrison, that the great 

 Veronese virtuoso Girolamo Fracastoro (Fracastorius), who " shares 

 with Leonardo de Vinci the honour of being the first geologist to 

 see fossil remains in their true light (1530)," and "was also the 

 first scientist to refer to the magnetic poles of the earth (1543) " in 

 a treatise " De contagione" (1546), "states with wonderful clair- 

 voyance the modern theory of infection by a micro-organism 

 (seminaria contagionum)," thus anticipating Kircher by about 

 112 years. Garrison, in a footnote, adds : " It is to be remembered, 

 however, that Fracastorius nowhere refers to the latter as living 



* Ars magna lucis et umbrae, Romse, 1646 ; Scrutinium . . . pestis, Romae, 

 1658. 



t An Introduction to the History of Medicine, by Fielding H. Garrison, 

 A.B., M.D., 1913. 



X Vorlesungen die Geschichtlicbe Entwickelung der Lehre von den Bacterien. 

 Leipzig, 1887, p. 2. 



