IN a letter published in NATURE of July 13, 1899, the author communicated some of the results he had obtained in measuring the electrical resistance of the blood. These results showed that the average resistance of normal blood at 60° F. measured by Kohlrausch's method in the apparatus used amounted to 550 ohms, while the specific resistance was 93.5 ohms. Further, a marked change was observed in pernicious anæmia, the resistance in this disease falling to about one-half (300 ohms) that of normal blood. The author has shown (Proceedings of the Royal Society of Edinburgh, December 21, 1891) that the electrical resistance of the urine in this disease is greatly increased (about 100 ohms specific resistance instead of the normal 45 ohms); hence we have the striking fact that, while the urine contains too few salts, the blood contains an abnormal amount. The kidneys, then, must obviously be in fault. In a patient, aged fifty-one, suffering from pernicious anæmia, under the care of Dr. A. James, in the Edinburgh Royal Infirmary, the blood resistance, measured on February 25, 1902, amounted to 300 instead of to the normal 550 ohms. The resistance of the urine, measured at the same time, amounted to 88 ohms instead of to the normal 45 ohms. The blood corpuscles numbered 900,000. The blood resistance in diabetes mellitus is high, like that of the urine. A number of experiments have been made by me to ascertain the time occupied by ingested sodium chloride to reach the blood. The blood resistance in five cases was measured before taking 30 grains of the salt and at five-minute intervals afterwards. The average time taken for the first lowering of the resistance of the blood was 15.4 minutes, and the maximum effect was produced in 21.4 minutes.

To obtain permission to re-use content from this article visit RightsLink.

Publication history

DOI

https://doi.org/10.1038/066127b0

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.