Some observations upon the test for choline in human blood : (abstract) / by R.W. Allen and Herbert French ; (communicated by M.S. Pembrey).

  • Allen, R. W., 1876-1921.
Date:
1903
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Licence: In copyright

Credit: Some observations upon the test for choline in human blood : (abstract) / by R.W. Allen and Herbert French ; (communicated by M.S. Pembrey). 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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    Journal Physiology, Vol. XXX. \^From the Proceedings of the Physiological Society, Nov. 14, 1903.] Some observations upon the test for choline in human blood. (Abstract.) By R. W. Allen and Herbert French. (Communicated by M. S. Pembrey.) From the Physiological Laboratory, Ckty's Hospital. Professor Halliburton and Dr Mott have published extensive researches on the chemistry of nerve degeneration in the Croonian Lectures of 1900 and 1901, and in the Philosophical Transactions of the Royal Society 1899 and 1901, and have devised a test for choline in the blood. The details of this test will be found in an article by Dr Mott in the Archives of Neurology, vol. ii. p. 859. The principle of it is to extract the blood four times in succession with absolute alcohol, to obtain the choline free from potassium, to precipitate the choline as choline platinochloride, and to crystallise the latter from 15 7o alcoholic solution. The crystals are yellow octahedra, and are readily seen under the low power of the microscope. In the original description of the test the choline platinochloride was washed by decantation in absolute alcohol, before redissolving in 15 Vo spirit and crystallising; a slight modification of the method of washing has since been introduced, namely to evaporate the absolute alcohol from the precipitated choline platinochloi ide at 40° C., to wash the dried residue with absolute alcohol, to redissolve the choline platinochloride in 15 ®/o spirit, and to allow the latter to crystallise spontaneously. This process, exact details of which will be given in a subsequent paper, has been employed throughout the present series of experiments ; and the quantity of blood used has been 60 minims, or about 4 c.c. Dr Mott states that the yellow octahedral crystals are obtainable from 5 C.C., or less, of blood from persons in whom active nerve tissue destruction is taking place; whereas “using 10 c.c. of normal human blood the results are practically negative, although frequently a few small octahedra may be found on careful examination.” Wishing to investigate the value of this te.st from the clinical point of view, we succeeded in obtaining yellow octahedral crystals from a series of patients suffering from various nerve disorders. On the other hand, we also succeeded in getting similar crystals from 4 c.c. of our own blood, and from that of two apparently healthy students. This did not agree