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THE FARMER'S MAGAZINE. 



is supposed that ten or even fourteen days may 

 thus elapse after the period of infection betore the 

 disease becomes outwardly apparent. This parasite 

 theory, Mr. Karkeek observed, received some sup- 

 port from the little that was known concerning the 

 properties of parasites : and this was a subject of 

 mucli practical importance to the farmer. In the 

 first place, such sources of infection were destroyed 

 by a temperature above 120 degrees Fahrenheit, 

 and also by strong chemical agents, especially 

 chlorine. Their activity was also impaired by cold 

 and by free ventilation. On the other hand, 

 warmth, closeness, and filth, increased the virulence 

 of the contagion, and became as it were a nursery 

 of pestilence. Nothing tended to promote the 

 spread of an infectious disease, such as pleuro- 

 pneumonia, more than the crowding together of 

 cattle which were affected by it. Each of those 

 animals was a separate source of contagion, and 

 the air would be contaminated in proportion to 

 their combined action. It might be asked, how 

 the empoisoned air produced its morbid results ? 

 He answered — not by direct irritation of the lining 

 membranes of the air passage, but by specific 

 action on the blood; which fluid, thus acted on, did, 

 by its changed condition, virtually, though not 

 immediately, affect the pulmonary tissue. In proof 

 of the assertion that vitiated atmosphere does not 

 act as a direct irritant to the pulmonary tissue, or 

 mucous membrane of the air passages, Mr. 

 Karkeek remarked that the usual syrajjloms of 

 catarrh or bronchitis are never the precursors of 

 pleuro-pneumonia. And again — if vitiated air 

 acted as a direct irritant of the pulmonary tissue, 

 both lungs would be equally affected ; whereas it 

 was well known that the disease was very partial — 

 affecting more frequently the right lung than the 

 left. Hence, pleuro-pneumonia could not be con- 

 sidered as an inflammatory disease, in the strict 

 meaning of the term. It might be asked why this 

 aerial poison affected only the lungs ? This was a 

 question not only easily answered. This much 

 was known, that the choleraic poison acted on the 

 intestinal canal, the poison of small-pox re-acts on 

 the skin; that of glanders on the mucous mem- 

 branes of the nasal cavities, while the poison of 

 pleuro-pneumonia acts on the lungs. He had 

 already stated that pleuro-pneumonia could not be 

 considered an inflammatory disease, in its origin ; 

 and of this, the absence of all ordinary symptoms 

 of pneumonia was proof; but there could be no 

 question that inflammation was one of the results 

 of the disease. It was more frequently regarded 

 as a dropsical, than as an inflammatory disease. 

 Evidently the empoisoned air produced consider- 

 able debility of the vascular part of the lungs, and 

 serum was effused almost immediately; hence the 

 dropsical character of the disease. As it progressed, 

 inflammatory action was set up, accompanied by 

 congestion, with effusion of lymph and serum into 

 the interlobular structure of the lungs and the 

 cavity of the chest. He was of opinion that this 

 serous effusion took place before the animal's 

 health was observed to fail. Proprietors of cattle 

 should therefore be early and late with their stock, 

 when pleuro-pneumonia prevails in a district, 

 narrowly watching the slightest indication of ill 



health. The usual symptoms he described were ; — 

 A slight, but husky cough would be occasionally 

 observable about this time, and perhaps the breath- 

 ing would be with increased effect, as if the animal 

 had undergone some unusual exertion. In milch 

 cows, besides the above symptoms, there would be 

 a diminished supply of milk. As the disease ad- 

 vanced, the cough became more troublesome and 

 husky; the respiration became hurried, the pulse 

 increased and oppressed, the appetite diminished, 

 rumination suspended, bowels constipated, and the 

 surface of the body chilly. The disease still ad- 

 vancing, the respiration became more difficult, 

 laboured, and painful; the poor animal was fre- 

 quently found lying, the head protruded, the mouth 

 covered with frothy saliva, the muzzle cold, rigors 

 frequent, and the pulse rapid and indistinct. Ap- 

 proaching death was shown by moaning, grinding 

 the teeth, loathing of food, coldness of the extremi- 

 ties, wavering pulse, distressed breathing, liquid 

 stools, and distention of the bowels. From this 

 description of this terrible disease, it must be 

 evident that blood-letting could be useful only at 

 its commencement ; bleeding should be early, or 

 not at all ; at the very beginning of the disease it 

 might do good, but at its later stages bleeding 

 would but hasten its fatal termination, since in 

 proportion to the extent of dropsical effusion 

 would be the debility of the patient. It was sup- 

 posed by Mr. Simonds, of the Royal Veterinary 

 College, that early bleeding might withdraw a por- 

 tion of the vitiated fluid that had laid the founda- 

 tion of the disease. Another remedy frequently 

 adopted was the use of purgative medicines. In 

 most diseases affecting the ox tribes, it was found 

 that gentle aperients were beneficial ; but in pleuro- 

 pneumonia, strong purging should be avoided. 

 Diuretic medicines might be useful, as in dropsical 

 diseases, for stimulating the kidneys to increased 

 action. He had little faith in sedative medicines or 

 diaphoretics in this disease ; but diffusible stimu- 

 lants and tonics were valuable remedies, at the 

 commencement of the disease, after the operation 

 by purgatives. In the latter stages of the disease, 

 vegetable and mineral tonics would be found useful. 

 A veterinary friend had used creosote with con- 

 siderable success; he (Mr. Karkeek) could be dis- 

 posed to try its effect when opportunity offered. 

 After speaking of the necessity of occasional re- 

 laxation of the bowels, in connexion with the use 

 of the above medicines, Mr. Karkeek further 

 recommended the application of a seton to the 

 " dew-lap," and of bhsters to both sides of the 

 chest. In conclusion Mr. Karkeek remarked that 

 there should be no specific for this disease; and 

 that he who should undertake its treatment without 

 a knowledge of its nature, and of the structure and 

 functions of the organ it affects, would act like an 

 ordinary artisan who should set about the repair- 

 ing of a watch, the wheels and levers of which he 

 had never investigated. Inattention to contagious 

 diseases had occasioned much mischief and loss of 

 property ; and there could be no doubt that, if 

 proper precautions were taken on the first appear- 

 ance of pleuro-pneumonia in any neighbourhood, 

 its ravages might be considerably mitigated. On 

 the outbreak of a disease of this kind on a farm. 



