THE 



POPULAR SCIENCE 

 MONTHLY. 



DECEMBER, 1876. 



FERMENTATION AND ITS BEARINGS ON THE PHE- 

 NOMENA OF DISEASE. 1 



Br JOHN TYNDALL, LL.D., F. E. S. 



IN a book with which we are all familiar, amid other wise utter- 

 ances, this one occurs : " Cast thy bread upon the waters ; for thou 

 shalt find it after many days." In more senses than one this precept 

 is illustrated by my presence here to-night. Firstly, in a general 

 sense, I stand indebted, morally and intellectually, to the poets, his- 

 torians, and philosophers, of Scotland. Secondly, in a special sense, 

 it so happens that one of the first rootlets of my scientific life derived 

 its nutriment from this city of Glasgow. In early youth it was my 

 ambition to qualify myself for the profession of a civil engineer, and 

 as I grew up one of my aids toward the attainment of this object was 

 the study of a periodical then published in Glasgow, and called The 

 Practical Mechanic's and Engineer's Magazine. In that journal I 

 read, with an interest unfelt before, a series of essays on various de- 

 partments of science on anatomy and physiology, on geology, on 

 mechanics, on arithmetic, and on natural philosophy and chemistry. 

 Biography and history were also included, while in detached articles 

 various collateral subjects were discussed, such, for example, as the 

 difference between Newton and Leibnitz as to the measure of moving 

 force. It was there that I first learned what Leslie had done in Edin- 

 burgh, and what Davy had done in the Royal Institution. And I 

 can now call to mind the day and hour when the yearning to possess 

 such apparatus as Leslie and Davy possessed, and to institute with 

 it such inquiries as they had instituted, rose to a kind of prophetic 

 strength within me prophetic, for it has come to pass that my own 

 studies as a scientific man have been in great part pursued in that 

 particular domain which had been enriched by the discoveries of Les- 



1 A discourse delivered before the Glasgow Science Lectures Association, October 

 9, 18*76. 



VOL. X. 9 



