46 The Management and Treatment of the Horse, 



the irritant are most severely affected. So should we find 

 it in influenza if it was caused by some irritant or mor- 

 bific poison in the air. But what does post mortem ex- 

 aminations of true influenza cases prove to us ? They 

 show us unmistakably that fine delicate membranes in the 

 air cells are nearly always perfectly free from disease. Fre- 

 quently we find these tissues in a state the very reverse 

 of congestion, inflammation, or tumefaction. They are of 

 a lighter colour, are less in weight, less in bulk, than when 

 in health, and even in those cases where we have 

 hydrothorax hydrops pericardii, this has not been pre- 

 ceded by the slightest inflammatory action it has 

 exhaled out of the surfaces and not exuded. I look 

 upon these as almost, if not quite, proof positive 

 that it is not attributable to a morbific poison or to a 

 prutrescence in the atmosphere. I am of opinion that the 

 true cause of influenza must be looked for in the peculiar 

 condition of the atmosphere, and the favourable state of 

 the skin and coat in the animal itself. I consider that 

 the primary cause of this epizotic, is a deficiency of elec- 

 tricity in the atmosphere during the whole of the period 

 the distemper is prevalent ; and that during the time 

 that such deficiency exists an insensible influence is ex- 

 erted upon all animals, and the degree they are affected 

 is in proportion to their susceptibility and favourable con- 

 dition. The effects it produces is in the first place felt in 

 the nervous system, and secondly in the vascular system. 

 The manner in which it affects the system is by robbing it 

 of a certain quantity of animal electricity in order to effect 

 equilibrium. A chill is experienced while this extracting 

 process is going on, a creeping sensation is felt in every 



