An experimental inquiry, into the principles of nutrition, and the digestive process / by John R. Young.

  • Young, John Richardson, 1782-1804.
Date:
1803
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry, into the principles of nutrition, and the digestive process / by John R. Young. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    Theiii external absorption was ascertained in another manner ; by exposing them in damp crass during the night, after being previously ex- hausted bv keeping them from water, they always regained their original weight, or the loss they sustained by being kept dry. Having thus ascertained that frogs are nourished by an external absorption of water, it occured that on this principle we might explain how snakes are supported many months, without eating the least particle of food. Dr. Barton has kept a rattle snake for eighteen months during all which time it never eat any thing.—And I my- self kept a copper snake during the last summer, for more than three months, all which time it re- fused to cat, though its natural food was frequent- ly presented to it. This occurence appeared quite inexplicable to me, how action and excretion could go on such a length of time when no food Mas taken : I was led therefore to suppose it could not have abstained from food all this time, but must have occasionally have caught insects, that might have crawled or fallen into its cage ; but I had no reason to have recourse to these conjectures, when I heared of the above fact ac- curing under so careful an observer as Dr. Bar- ton. With a view of ascertaining whether snakes derive nourishment from an external absorption, the following experiment was performed. A snake was kept confined in a dry jar for five days; at this time it was lean and quite in- active, and weighed one ounce four drams, and fifty eight grains. It was now extended upon a narrow board, on which it was laced firmly ; in this situation its whole body, except about three