A manual of infectious diseases / by E.W. Goodall and J.W. Washbourn.

  • Goodall, E. W. (Edward Wilberforce), 1861-
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: A manual of infectious diseases / by E.W. Goodall and J.W. Washbourn. Source: Wellcome Collection.

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    temperature rapidly rises many degrees above normal. But apart from contraction the muscles are constantly producing heat; and when we consider their bulk in relation to the other tissues, there can be little doubt that they are the chief source of the heat of the body. Next to the muscles come the secretory glands ; and it has been shown that the blood in the hepatic veins, as they leave the liver, is hotter than any other part of the body. The amount of heat produced can be measured directly or indirectly. Indirectly, it is measured by estimating the carbonic acid given off, or more accurately the oxygen consumed; and from these data the amount of heat pro- duced can be ascertained. The production of heat can be directly measured by a calorimeter, which consists essentially of a large metal chamber, in which the animal is placed. This chamber is surrounded by a narrow chamber containing air, and from the expansion of this air the amount of heat given off by the animal can be estimated. Provided the temperature of the animal remains constant during the experiment, the heat given off is equal to that produced, and thus the production of heat can be measured. While heat is constantly being produced in the body it ,is also constantly being lost. The chief channels of loss are the skin and the lungs; for we may neglect such slight loss as occurs through the warming of the urine and faeces. From the skin heat is lost by conduction, radiation, and by the evaporation of the sweat; from the lungs heat is lost by the warming of the expired air, and by the evaporation of its moisture. It has been estimated that of the total heat lost more than three-quarters passes through the channels of the skin.