The mischief of bad air.

Date:
[between 1850 and 1859?]
Catalogue details

Licence: Public Domain Mark

Credit: The mischief of bad air. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    HOW THE LIVING BODY GETS WARMED. }J pipes and in the blood, heat-fanning air, as well as supporting food. When air reaches the living flesh and nerves, by thus flowing to them in the blood-streams of'the supply-pipes, it sets up those changes of substance m their structures which lead to the production of movement, and feeling, and other kinds of living power. When it reaches the dissolved fuel, con- tained in the blood and in the various little furnace- chambers of the laboratory, it sets np those changes m the fuel which lead to the production of warmth. ±he fuel is slowly burned in the blood and in the chambers of the frame, and there gives out warmth as a fare does whilst it is burning in a grate This warmth consequently heats the blood, and the warm blood carries its heat wherever it goes. The entire body thus becomes as warm as the blood, or nearly so Now where do you think all the heat originally comes from, that is procured from burning fuel > The heat is stored away in the fuel, as one of the ingre- dients ot its composition, until it is burned. But where was the heat obtained from, which is stored up in the fuel? Of course, when the fuel was made, that heat-store had to be supplied to it, as well as its other ingredients. First let us see when and how the fuel was made, and perhaps we shall then be able more perfectly to understand this matter of its warm- nig qualities and power. In the case of coal, it is not a very difficult task to trace the stored-up heat to its source. But what a surprizing truth it is, which becomes apparent when the task has been performed. The heat is, so to speak, bottled-up sunshine ! Coal is dug up from deen mines hollowed out in the earth. But at one time it was wood, growing on the outer surface of the globe and covered with foliage which was spread out into the genial air. Traces of the leaves and stems from which it has been made, are still discovered in its substance. Long centuries ago, the vast forests