Dr. W. Stirling and A. Rannie. 



the corpuscle, even when the whole of its granular contents had 

 passed out. The nucleus generally remained within the envelope, and 

 became tinged of a yellow colour. The intranuclear plexus of fibrils 

 was also revealed. (PI. 1, fig 1, g.) The envelope of a corpuscle devoid 

 of its granular contents was observed to be tinged of a yellow colour, 

 and to show a double contour. A similar appearance was observed 

 around the nuclei. The remaining corpuscles ultimately became com- 

 pletely disintegrated, and the field of the microscope became covered 

 with free nuclei, granular colouring matter, and fragments of 

 envelopes sometimes containing nuclei. (PI. 1, fig. 1, i.) Sometimes an 

 envelope was seen entire but with a rent in its side extending half 

 through it, and through which its contents had escaped. (Fig. 1, h.) 

 Sometimes a mass of granules was observed with a dark line partially 

 enveloping it. The dark line represented a highly refractive envelope 

 now distinctly shown — perhaps produced — by the action of the pyro- 

 gallic acid. 



It is an interesting question to determine why and how this sudden 

 protrusion of a portion of the coloured corpuscles is produced at one 

 part of the circumference. That a process of endosmosis goes on is 

 shown by the corpuscles assuming a globular form, but that of itself 

 is not enough to account for the sudden protrusion already referred 

 to, for water and many other fluids also produce endosmosis, but give 

 rise to no such ejection of the contents of the corpuscles. The 

 pyrogallic acid obviously has some chemical effect on the corpuscular 

 contents, and it is just probable that the envelope of the corpuscle is 

 not perfectly uniform in its resistance all round. We are inclined to 

 view the above described phenomenon in connexion with the spots or 

 thickenings described by Dr. Roberts as occurring in the wall of blood- 

 corpuscles under the action of magenta solution, and also with the 

 curious spots observed by us in the corpuscular wall after the action of 

 gallic acid. It is to be noted that no contraction or diminution of 

 bulk of the corpuscle is observable as coincident with the extrusion of 

 the mass, which, however, is relatively so small that it would scarcely 

 visibly affect the diameter of the corpuscle. The various effects are 

 shown in PI. 1, fig. 1. 



Seeing that tannic acid has already yielded such remarkable results 

 in the hands of Dr. Roberts, and that pyrogallic acid gave rise to 

 equally peculiar phenomena, it occurred to us to ascertain the effect of 

 a substance closely related to both, viz., gallic acid. [Wedel* also 

 recognised that pyrogallic acid causes a separation of the hemoglobin 

 from the stroma.] 



Gallic Acid. 



A saturated solution of gallic acid causes the corpuscle to become 

 * Hermann's 11 Handbuch der Plijsiologie," vol. 4, p. 18, 1880. 



