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IV.—Miscellaneous Observations on the Blood

Published online by Cambridge University Press:  17 January 2013

Extract

On a fluid of so much importance as the blood, observations with any pretension to accuracy can hardly be too often made and repeated, more especially when we consider its great instability, its little uniformity, and the differences of opinion entertained by physiologists respecting some of its most remarkable properties.

Such is the persuasion which has influenced me in engaging in the present inquiry, and in submitting its results to the Society.

Type
Transactions
Copyright
Copyright © Royal Society of Edinburgh 1865

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References

page 20 note * Vol. ii. p. 184.

page 23 note * Anatom. and Physiolog. Res. vol. ii. p. 214.Google Scholar

page 25 note * I have found the temperature of the blood of a pig, flowing in a full stream, 106°. The pig was in high condition; the blood used was from it.

page 26 note * Hewson's Works, p. 25.

page 26 note † Physiological Researches, p. 369.

page 31 note * When well-washed fibrin, still slightly coloured by the colouring matter of the blood, is placed under the microscope, it appears to consist of translucent granules forming under gentle pressure a connected tissue. On the addition of aqua ammoniæ it becomes clear and transparent, like jelly, with a brightening of its colour. Compressed, it shows elasticity, and when extended by continued pressure, so as to be very thin, its appearance is hyoloid; no granules are to be seen in it except a few scattered ones, which, it may be, were derived from blood corpuscles.

Fibrin which has been rendered viscid by ammonia, after the removal of the ammonia by repeated washing, gradually contracts, and from being transparent becomes, in consequence of condensation, opaque, or nearly so. Thus contracted it often exhibits an imitative form, like that of hydatids. Its retention of the colouring matter of the blood is remarkable; it is greater even than that of the capsule or walls of the corpuscles.

page 32 note * Serum of blood, such as I have tried, and I have made many trials, on first evaporation affords a residue which is almost entirely soluble in water, but on repetition again and again, it is so altered as to become insoluble.

page 32 note † Ammonia does not appear to arrest entirely the putrefactive decomposition of the blood: thus a mixture of 257 grs. of blood, and of 2·5 grs. of aqua ammoniæ, the subject of the third experiment, after having been kept twenty days, had, besides an ammoniacal odour, an offensive smell, indicative of incipient putrefaction. In great excess, it certainly retards the change in the instance of the entire blood and in a great degree in the instance of the fibrin, and in that of the serum. A portion of the coagulum left from the first experiment and kept three months, had, after the ammonia had been rapidly expelled, an offensive odour, only in a slight degree.

page 33 note * Brande, and Taylor's, “Chemistry,” 1863, p. 833.Google Scholar

page 33 note † In one experiment, the clot, from six ounces of bullock's blood, after draining off as much as possible of the serum, was cut into small pieces and macerated in water, using the ordinary means to separate the fibrin. The solution formed, loaded with colouring matter, was evaporated at a temperature below 160°, until reduced to the sp. gr. 1033; its alkaline reaction then was very slight, so as to be hardly discernible when the delicate test-paper used was dried.

After evaporation of the solution to dryness, the residue was exposed to the fire in a platina capsule. In its charred state, after it had ceased to burn with flame, its particles were slightly attracted by the magnet, the coal after cooling having been reduced to powder. The particles of its ash, after the charcoal had been burnt off, were also similarly attracted. The magnet used, it may be mentioned, was a needle that had been magnetised by a fœtal torpedo, and which (as the result showed) still retained its power, after the elapse of 32 years. The residuary ash, on the addition of a little water, showed so feeble an alkaline reaction, that it was hardly as well marked as that of the saliva.

page 34 note * Lehmann's, “Physiological Chemistry,” ii. pp. 160, 212.Google Scholar

page 34 note † Proceedings Roy. Soc. Vol. xii. p. 580.Google Scholar

page 35 note * See the author's Anatom. and Physiolog. Research., ii. 196.Google Scholar

page 35 note † Idem, vol. i. p. 123.