INFLUENZA IN HORPE?. Zod 



iiicousisteut witli general maguetic couditious." And liow often do we 

 aee thunder-storms occurring day after day for a lengtli of time without 

 the supervention of influenza. It is not at all improbable that this elec- 

 tric condition of the atmosphere had something to do with the develop- 

 ment of the epizootic ; but in view of all the known facts, and of our 

 experience of the past, we can only look on it as predisposing the system 

 to the attack of a poison which previously existed, but had remained 

 latent for want of a receptive subject. Considering the feverish condi- 

 tion of the system in times of great electric tension, the amount of ozone 

 resulting from electric discharges, and the known action of ozone on the 

 respiratory mucous membrane, the doctrine is at least plausible that the 

 diseased condition and lowered vitality of this membrane at such a time 

 laid it open to the attack of the poison. But in support of this theory 

 as universally operative, we must assume either a supervention of this 

 electrical derangement at each place whenever an animal is attacked, or 

 that the reception of the poison into the animal body changes its char- 

 acter and intensifies its virulence. This gradual march of the electric 

 tension over the continent seems an extravagant and unwarrantable 

 assumption. The acquisition of increased potency or virulence, by pass- 

 ing through an animal bpdy, is not altogether incompatible ^vitll what 

 we know of the varied development of some of the lower forms of life 

 in different media. 



It will bo observed that this hypothesis of the etiological importance 

 of electricity and ozone does not touch the question of the primary 

 origin of the poison. It assumes the poison to be already in existence, 

 and that these agencies merely lay the system open to receive it, as do 

 impure air, exhaustion, unsuitable food, and other health-depressing 

 causes. AYhatever the significance of the electrical disturbances at 

 Toronto in September, the fact ought to be recorded for the guidance 

 of future observers. 



Progress from east to west or from west to east. — The old doctrine 

 was that influenza always extended from east to west, as it had been 

 repeatedly traced over Asia into and through Europe. The epidemics 

 of 1781, 1800, and 1833, were remarkable examples of this. Yet it has 

 often followed an opposite course. The epidemic of 1768 prevailed in 

 America before it reached Europe, and "Webster claims the same course 

 for those of 1757, 1761, and 1781. Gluge, from an induction of all the 

 epidemics known to have occurred for three hundred years, concluded 

 that the general course was from west to east. The recent equine 

 influenza has spread from Toronto in a direction east, west, and south, 

 and indeed any conclusions based on the direction pursued by the 

 malady must be given up. 



Contagion. — Is there a specific contagion '? This is manifestly a ques- 

 tion of vital importance with reference to the influence of the above 

 alleged causes. If there is a contagion which may exist in the body of 

 the sick animal, increase there, and be the means of communicating the 

 malady to an indefinite number of sound stock, all our theorizing on 

 noxious gases and putrid fogs, inclemencies and extreme vicissitudes 

 of the weather, excess of ozone, magnetic disturbance, and the like, 

 will be of small account. Indeed no one of the conditions we have 

 been considering, nor all of them put together, can explain the regtdar 

 progress of such as the recent ei)izootic, step by step, from a given point 

 of origin, over the whole Atlantic slope of the continent, extending 

 over a period of three months, and without being materially influenced 

 by locality, soil, altitude, weather, or climate. No such condition will 



