Observations on the functions of the liver : more especially with reference to the formation of the material known as amyloid substance, or animal dextrine, and the ultimate destination of this substance in the animal economy / by Robert M'Donnell, M.D.

  • McDonnell, Robert, 1828-1889.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the functions of the liver : more especially with reference to the formation of the material known as amyloid substance, or animal dextrine, and the ultimate destination of this substance in the animal economy / by Robert M'Donnell, M.D. 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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    right side of the heart, it is gently moved up and down while the blood is being drawn into the pipette attached to it; by this manoeuvre the operation is facilitated, and the blood is not prevented from entering the catheter by the lining mem- brane of the heart or vein being sucked against the eye of the instrument. The blood thus obtained from the right side of the heart was treated with three or four times its bulk of proof spirit, which was filtered off, the residue being repeatedly washed with additional spirit; the filtered spirit was evaporated to dryness on a water bath, and the dry residue treated with distilled water, which was tested by Fehling's solution for the presence of sugar. The result was, that in twelve experiments made on dogs, which for some weeks before had been fed exclu- sively on meat, traces of sugar were found in five ; no sugar was discoverable in the blood of the remaining seven. None of these animals were killed at the time; but there is no reasonable doubt but that, as they were healthy animals, more or less of the amyloid substance existed in the livers of every one of them, and that, probably, the traces of sugar in five were due to the dislodgement of some of it, in consequence of unavoid- able struggling, and its transformation into sugar in the blood. In experimenting on the tissue of the liver of warm-blooded animals immediately after death by pithing, no matter what rapidity, precision, and care are exercised, it is not possible to obtain results which enable one to state that absolutely no sugar is present; but the quantity, under certain circumstances, is so small as to be quite incapable of being estimated. WTien we consider the extraordinary dehcacy of the tests for sugar now in use, such a result is what must be naturally expected, when it is recollected that the temperature of the pithed animal is highly favourable to the prompt change of the amyloid sub- stance into sugar, and that in boiled starch the presence of sahva is in a few seconds able to give rise to sugar transfor- mation. In repeating Dr. Pavy's experiments on the tissue of the Hver by freezing it or boihng it, with the least possible loss of time, after death I have preferred to operate on cats rather than rabbits, because more or less sugar almost invariably pervades the tissues, or is discoverable in both the venous and arterial blood of these vegetable feeders. Cats, therefore, for some time fed 4