168 ANNIVERSARY ADDRESS 



perhaps our sun's sun, in going his rounds, may experience in 

 some places so great an amount of force that the numerous suns 

 which attend him, in making use of it, may create so much heat 

 that life in all the solar systems may be burnt out, the firmest 

 rocks vitrified, and all water evaporated. After a time the suns 

 may come into a part of space where force is so deficient that all 

 life may be frozen. I can imagine that Alcyone and our sun, 

 with others that circulate round him, may come again into a part 

 of space where force is just of the right amount for life, and then 

 I can conceive it possible that life would spontaneously arise in 

 obedience to the laws at first impressed on imponderable and 

 ponderable matter by the Omnipotent Creator. I do not imagine 

 that life would suddenly arise. The immense interval which 

 separates the living and the non-living, I think, would be too great 

 for that, and the fiist appearance of life I should expect would 

 be ultra-microscopic. But this is, perhaps, vain speculation. I 

 must get back to disease. 



When a germ once gets entrance into our body by our breath, 

 or by our drinking a solution of sewer gas, it undergoes a period of 

 incubation or vegetation, and it causes a regular round of changes 

 in obedience to the law of circular motion. "With regard to the 

 Trichina spiralis (a pretty object under the microscope), when the 

 germs or ova are eaten in raw meat, they have on more than one 

 occasion caused a fatal epidemic. I have read that " this little 

 parasite was first discovered at St. Bartholomew's Hospital." I 

 think this an error, for I distinctly recollect having Trichina spiralis 

 pointed out to me in the dissecting room of Guy's, in October, 

 1847, and I was told that it had been discovered some years before 

 by that eminent surgeon and anatomist, the late John Hilton, 

 whom we may regard in some sense as a Hertfordshire man, as he 

 began his professional career at St. Albans. I must not pursue the 

 subject of the plan of disease any further ; I will only quote Dr. 

 Mason Good, who, when speaking of the critical days in fever, 

 says: "If we examine the phenomena of the animal economy as 

 they occur in a natural series, we shall find that they are in almost 

 every instance governed by a periodical revolution." 



The theory I have brought before your notice I have only 

 sketched in faint outline, and I have not attempted proof. If I 

 had time and ability, I should like to investigate the subject from 

 various points of view. I should endeavour to find out the number 

 of the distinct glacial periods, and try to discover any periodicity 

 in them, and what relation in geological time they bore to each 

 other and to the astronomical position of the sun. I should study 



