Section III., 1894. [ 3 1 Trans. Roy. Soc. Canada. 



I. — Presidential Address. 



By Professor G. P. Girdwood, Af.D. 



(Read May 22, 1894.) 



Gentlemen : — A year ago you did me the honour of electing me your President for 

 this, the thirteenth meeting of tliis section, and I heartily congratulate the memhers that we 

 are permitted to meet again without having to deplore the loss of any of our number, and 

 that we have to welcome amongst us as members, elected at the last meeting, the Rev. Mr. 

 De Foville and Mr. 0. H. McLeod. 



One of the duties devolving on the President, at least expected of him l)y custom, is to 

 deliver an address. Frefpiently such an address takes the form of a résumé of the work 

 done during the j'ear in the department of science associated with the meeting. In this 

 section, embracing, as it does, so extended a field as is included in Mathematics, Physics 

 and Chemistry, it is manifestly impossible for one man to read even the records of the 

 immense amount of work accomplislied by so many students as are found working under 

 the above headings ; indeed, the giant strides being made at the present day in all branches 

 of knowledge are such, that at the end of each year, we may, like some new Rip Van 

 Winkle, as if just awakened, wonder where we are. 



In the pi'ofession of which I have the honour of being a member, that of medicine, are 

 emljraced many handmaid sciences, of which Chemistry and Physics are among the most 

 prominent — and to them tlie profession is indebted for some of its most important recent 

 discoveries. 



"In 1868 Borgman and Schmeideljcrg obtained sepsinc, an alkaloid, from putrid l)eer." 

 " Quelzer and Sonnenscheim discovered in animal tissue another resembling atropine." In 

 1870 Selmi and Gautier brought forward their experiments on tliese subjects and from that 

 time to the present, these poison(ins alkaloids have been investigated and led to our present 

 knowledge of the subject. 



Many years ago cliolcra, and the various febrile diseases, were looked upon as the 

 results of the action of cei'tain ferments, wliieli like yeast reipiired definite conditions for 

 their development, amongst which heat and moisture were two of the prominent factors ; 

 that once started, they ran their course to a certain termination in a specified time, but that 

 without the concurrence of all the necessary conditions the disease was not produced. This 

 was a theory established by observation and analogy — time has demonstrated the truth of 

 that theory and by the aid of the more enlightened use and the greater perfection of the 

 microscope, it has become possilde to identify in many cases the fungi which like the yeast 

 plant produce these diseases, whilst chemistry has enabled us to separate the results of the 

 growth of these fungi and to recognize the materials thus formed as [loisons, not only to 

 man and other animals, but to the fungus itself producing these changes. 



