1879-1 
British Association . 
691 
the effects of different changes of environment on one and 
the same species. The President then directed attention to 
the resemblances and differences which exist between the 
mind of man and the higher physical faculties of animals. 
In the Department of Anatomy and Physiology the Pre- 
sident was Dr. Pye-Smith, F.R.S., whose address attracted 
great attention. Biology, he remarked, is the science of 
the structure, the functions, the distribution, and the suc- 
cession in time of all living beings. If the proper study of 
mankind be man, he has learnt late in the inquiry that he 
can only understand himself by recognising that he is but 
one in the vast network of organic creation ; that intelli- 
gible human anatomy must be based upon comparative 
anatomy ; that human physiology can only be approached 
as a branch of general physiology, and that even the 
humblest mould or sea-weed may furnish help to explain 
the most important problems of human existence. Speak- 
ing of the relation of physiology to the national health Dr. 
Pye-Smith said that if the art of keeping a community in 
health is but the application of plain physiological laws, it 
is no less true that the art of restoring the health, curative 
as distinct from preventive medicine, rests upon the same 
basis. We now know that disease is, as the name implies, 
a purely subjective conception. The disease of a host is 
the health of the parasite, and we cure a human sufferer by 
poisoning the animals or plants which interfere with his 
comfor:. The same changes which in the old man are the 
natural steps of decay, the absence of which after a certain 
age would be truly pathological, are the cause of acute 
disease in the young. Pathology has no laws distinct from 
those of physiology. It clearly follows that all “ systems 
of medicine ” are in their very nature condemned. All that 
the art of medicine can do is to apply a knowledge of 
natural laws, of mechanics, and of hydrostatics, of botany 
and zoology, of chemistry and electricity, of the behaviour 
of living cells and organs when subjected to the influence of 
heat and of cold, of acids and alkalies, of alcohols and 
ethers, of narcotics and stimulants, so as to modify certain 
deviations from ordinary structure and function which are 
productive of pain, or discomfort, or death. Rational medi- 
cine, or keeping right and setting right the human body, 
must therefore rest upon a knowledge of its structure and 
its actions, just as a steam-engine or a watch cannot be 
mended upon general principles, but only by one who is 
familiar with their construction and working, and who can 
detect the source of their irregularity. With regard to the 
