To the VII. Title OF THE HISTORY.
THE specific Gravity of Humane Blood is more difficult to be ••etermin'd, than one would readily ••magine. For the Gravity of Blood may differ sensibly in several persons
Memoirs for the natural history of humane blood, especially the spirit of that liquor by Robert Boyle.
About this Item
- Title
- Memoirs for the natural history of humane blood, especially the spirit of that liquor by Robert Boyle.
- Author
- Boyle, Robert, 1627-1691.
- Publication
- London :: Printed for Samuel Smith,
- 1683/4.
- Rights/Permissions
-
To the extent possible under law, the Text Creation Partnership has waived all copyright and related or neighboring rights to this keyboarded and encoded edition of the work described above, according to the terms of the CC0 1.0 Public Domain Dedication (http://creativecommons.org/publicdomain/zero/1.0/). This waiver does not extend to any page images or other supplementary files associated with this work, which may be protected by copyright or other license restrictions. Please go to http://www.textcreationpartnership.org/ for more information.
- Subject terms
- Blood -- Early works to 1800.
- Cite this Item
-
"Memoirs for the natural history of humane blood, especially the spirit of that liquor by Robert Boyle." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A28998.0001.001. University of Michigan Library Digital Collections. Accessed May 6, 2024.
Pages
Page 34
according to their Sex, Age, Constitu∣tion, &c. And in the same person it may be varyed by the time of the year, and of the day, and by being drawn at a greater or lesser distance from a Meal, and by divers other Circumstances. But besides all these things there is a Mechanical difficul∣ty, if I may so call it, that attends the work we are speaking of. For the Blood begins to coagulate so soon af∣ter it is emitted, that 'tis scarce a practicable thing to weigh it hydro∣statically, either by immersing into it a Solid Body heavier than it self or by weighing the whole Blood in Water; the former way being oppo∣sed by the fibrous part of the Blood, and the latter by the Serum. And up∣on the same account it is somewhat (though not so much) difficult to compare with any accurateness, the weight of Blood, with that of water in a Glass, as also for other reasons which he that shall considerately go about to try it, will quickly find
Page 35
But however, since it may be a thing of considerable use, to have some tolerable Estimate, though nor an exact one, of the difference in Gra∣vity between Water and Humane Blood, by which so many parts of the Body, consistent as well as fluid, are by various changes of Tex∣ture both constituted and nourished. I shall subjoyn a Tryal, that this consideration invited me to make as well as I could. We took the Blood of a sound man emitted all at one time, and put the whole mass of it, as well the Serous as the Fibrous part, into an oblong Glass, of the fittest size and shape we could light on amongst several. And have∣ing suffered the Blood to rest till all was setled, and the many Bubbles vanished, we carefully mark'd with a Diamond that narrower part of the Glass, which the upper surface of the Blood reach'd to. Then we weighed the Glass and the Blood in a very good Ballance and having
Page 36
poured out the Blood (for other uses) and washed the Glass, it was filled with common Water to the lately mentioned Mark, and then weighed again in the same Ballance; afterwards the Water being poured out, the Glass alone was Counterpoi∣sed in the same scales, and its weight being deducted from each of the two formerly mentioned weights, the Wa∣ter was found to have weighed ℥ix. ʒvi. 50. Gr. And the Blood (equal to it in bulk) to have weigh'd ℥x. ʒij. 4. Gr. So that the difference between them being ʒiij. 14. gr. the Blood was beavier than so much Water, but about the 25th part (for I o∣mit the Fraction) of its own weight. But this Experiment, for the Reasons above intimated, deserves to be reite∣rated more than once.