Dress, with reference to heat : being a lecture written for, and published by the Australian Health Society / by Walter Balls-Headley.

  • Balls-Headley, Walter.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: Dress, with reference to heat : being a lecture written for, and published by the Australian Health Society / by Walter Balls-Headley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    the blood back to tlie lieart ; which indeed are unable to maintain their contracting power for more than a short period at a time, when dilatation ensues : these arteries and veins communicate by- means of very delicate vessels called capillaries, having no muscular coat at all. It is not therefore to be wondered at, that the heat withdrawn as above described should produce such an effect by its absence, which we call cold, that the powerful muscular coat of the surface arteries drives the blood out of themselves through to the capillaries and veins ; the blood in which latter vessels, being always blue as seen on the backs of the hands, gives the colour to parts chilled. Thus we speak of a man's nose as blue with cold. The excess of this kind of blood in a frozen or mortified part is the cause of its appearing black. Now the i)roper course of this blue blood in the veins is onward to the heart: by the heart it should be forced into the ai'teries of the lungs, to receive oxygen and be deprived of its carbon, forming heat in the process, by chemical change : thence back into the heart in a perfect state, to be by it forced through all the arteries of the body. Now, supposing the arteries of the surface of the body to be chilled by the removal of heat, and therefore contracted as before mentioned, and, similarly, that the vessels in the lungs be at the same time subjected to chill by breathing cold air, and to contract, it is evident that it must be somewhat difficult for circulation to continue in the same regular mode as before; for, while the ai'teries are forcing blood into the veins from behind, these tiibes ai*e, by dilatation of weariness after ])revious contraction, unable to maintain the onward curreiit of the blood : thus they become clogged, and the capillaries behind them engorged. This condition may be likened to that of a, thoroughfare, when the traffic is suddenly hastened in one part, but stopt in front; it is evident that a block must result. Medically, we call such a blocking of the blood-vessels a congestion ; and it depends upon the situation where this happens^ to the effect thereof. For instance, if it be in the blood-vessels about the nose, we call it a cold in the head ; if in the large air tubes of the lungs, we say we have a cold on the chest; if in the