Farther observations on the state of the blood after taking food.

  • Buchanan, Andrew, 1798-1882.
Date:
[1845]
Catalogue details

Licence: Public Domain Mark

Credit: Farther observations on the state of the blood after taking food. 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 serum from both bleedings was quite limpid, and of a deep amlier yellow. That fi'om the first bleeding had the deepest tinge; on supersaturating it with salt it became slightly troubled, but without losing its transparency, and at length showed pale flocks, which became whiter in colour as they subsided to the bottom. The serum from the second bleeding gave a precipitate, which was likewise flocculent, of a more decidedly white colour, and more abundant, although very insignificant in point of quantity when compared with the precipitates obtained after a full azotized meal. This experiment shows, that abstinence from food for twenty-four hours, by a person in good health, taking active exercise in the open air, reduces to a minimum, but does not altogether remove the precipi- table matter of the blood. The two other experiments suggested above, lead to the same conclusion ; and the last furtlier shows, that a very prolonged fast introduces a new complication into the question by occasioning an incipient decomposition of the blood. lu the beginning of August I got from a medical friend some serum from the blood of a man bled for a pleurisy, of which he died soon afterwards. It gave a scanty precipitate on being saturated with salt. On the 16th of August, a dog, which had been kept flfty-one hours without food, and had drunk little although allowed a free supply of water, was bled from the saphena, to the extent of about two ounces. The blood trickled slowly down the leg, and was coagulated in part before the whole had been received in the cup. Whether owing to this circumstance, or to the long fast, the serum was tinged deeply red, apparently from the coloming matter being dissolved, for it was quite transparent, and did not lose the colour by standing at rest. Salt gave a precipitate, although little abundant. We may infer then from these experiments, that it is not possible, without carrying fasting to a greater length than prudence or humanity permit, to deprive the blood altogether of its white precipitate. This conclusion is quite conformable to what our experience of the persist- ance of Iodine in the body would lead us to expect. It has, however, been ascertained that the white precipitate obtained from the serum of the blood by supersaturation with salt, is most abundant after a meal; that it is less abundant as the period of taking food has been more remote; and that, after a fast of twenty-four hours, it is very insignificant in quantity. Still farther, after certain kinds of food, such as eggs, casein, and white-fish, a much larger quantity of white matter is found in the sei'um than after certain other kinds of food, such as starch. Last of all, the characters of the precipitate vary, so that it may either be made to swim on the surface, or sink to the bottom, according to the kind of food. It appeal’s, therefore, not unreasonable to conclude, that this white precipitate proceeds from the food, being the newly digested nutritious matter introduced by certain aliments into the blood. The only other view that can be taken of the nature of this preci- pitate, is, that it is occasioned by the salt re-acting upon the albumen dissolved in the serous liquid. This view does not seem to mo recon- cileable with the great variations in the quantity of the precipitate.