On peculiar appearances exhibited by blood-corpuscles under the influence of solutions of magenta and tannin / by William Roberts, M.D.

  • Roberts, William, Sir, 1830-1899.
Date:
[1863]
Catalogue details

Licence: Public Domain Mark

Credit: On peculiar appearances exhibited by blood-corpuscles under the influence of solutions of magenta and tannin / by William Roberts, 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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    than a twentieth or thirtieth of the circumfierence ; but there was a considerable variation in its magnitude and distinctness. Very rarely two specks could be seen ; but the occurrence of adhering granules rendered the verification of this point extremely difficult. This description applies, so far as the inquiry has yet been prose- cuted, to the mammalian blood-disk generally, making allowances for differences in size. In the camel the macula occupied indiffer- ently any part of the oval outline. xlmong the oviparous classes, the blood of the fowl, frog, dace, and minnow has been most fully examined (see fig. 1, B); but the blood of the sparrow, duck, goose, and turkey was also searched, as well as that of the newt and carp. In all of these a tinted particle appeared, more or less constantly, in the cell-wall, when the corpuscles were treated with magenta*. The presence of a central nucleus in these classes caused the ma- cula to be invisible more frequently than in mammalia, inasmuch as it suffered eclipse when situated over or under the central nucleus. In the fowl, dace, and minnow it was found easy to bring out the parietal macula; in the fish two spots were not unfrequently seen. The macula was situated indifferently on any part of the periphery ; and sometimes it projected from the surface. When happily pre- pared the specimens were even beautiful. The central nucleus was dyed of the finest red; and on the delicate outline of the cell-wall hung the red parietal macula, offering a not altogether fanciful re- semblance to the astronomical figures representing the moon coursing in its orbit round the earth. At this stage of the inquiry it was conceived that an improved demonstration might be obtained by fixing the dye with a mordant, and then subjecting the corpuscles to a lavatory process, so as to get rid of the floating granules which so much interfered with the view. For this purpose a solution of tannin (which is one of the mordants for magenta used in the arts) was employed; and some advantage was found therein. When a solution of tannin, of 3 grains to the ounce of water, was added to blood that had already been dyed with magenta, it was found that the parietal maculae had their colour intensified, and that they became more conspicuous objects. The investigation was, however, not pushed any further in this direction, for it was found that tannin alone produced an even more remarkable effect than magenta. To this effect I now desire to draw particular attention. When a solution of tannin, of the strength of 3 grains to the ounce, was applied to human blood, or to that of the horse, ox, sheep, pig, or cat, the blood immediately became turbid; and when a drop was placed under the microscope the corpuscles were found greatly changed, as represented in fig. 2. Each corpuscle appeared to have thrown out a bright, highly re- * In order to bring out the best results, it was found requisite to modify the strength and quantity of the solution for the different kinds of blood. This doubtless depended upon the varying densities of the liquor sanguinis and cell- contents in different animals.