A report of microscopical and physiological researches into the nature of the agent or agents producing cholera / by T.R. Lewis and D.D. Cunningham.

Lewis, T. R. (Timothy Richards), 1841-1886.

Date:: 1872

Credit: A report of microscopical and physiological researches into the nature of the agent or agents producing cholera / by T.R. Lewis and D.D. Cunningham. Source: Wellcome Collection.

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$dealing with large healthy dogs wc calculate on losing about one in five through this cause alone. Moreover, the effects produced were of so contrary a character, even under pre- cisely similar conditions, that we feel convinced that any data of this kind obtained by experiments on small and deli- cate animals are extremely lialjle to mislead. This is a very unfortunate circumstance, not only be- , . . . r ,^ cause, as a rule, small animals arc and \moertamty of result. -i i i • n i more easily obtained and more man- ageable, but also because the observations on cholera-material hitherto recorded, and which have exercised great influence on the opinion of medical writers, and of the scientific world generally, have for the most part been derived from experiments on even more delicate animals than those above referred to. This drawback will be evident to all who may carefully peruse some of the following cases, more especially those recorded in connection with the attempts to produce infec- tion by the introduction of choleraic and other organic matters into the circulation. The unsnitableness of small animals for experiments involving section of minute and deep-seated nerves arises, to a great extent at least, from a Unsuitableness of smaU t nc j t ji i animals for nerve-section ex- oilierent causc, namely, the extreme periments. / n r»i • i i • -i tenuity oi nerve fibres m such, which in man are large and easily accessible, and are even moder- ately large in well-developed dogs. Size is of .still more im- portance, where, as in remarkable cases to be afterwards referred to, the section of a certain portion of a nerve appears to make such a vast difference in the result of the ex- periment. We have, therefore, selected the dog not only from its size, but also from the fact of its food being very Beasons for Having selected cloSCly allied to that of man, as dogs for tiiese purposes. being morc Suitable to experiments of the nature here alluded to, especially as the organic sub- stances hitherto experimented upon have not been in- troduced into the circulation through the digestive system. Had such a method been adopted, the tremendous powers of digestion of the native, pariah or Bedouin dog would have rendered any comparative data unmistakeably use-$