236 OF THE BLOOD: 



seems to take place through the surrounding liquid. 1 With dilute solutions 

 of common salt they become prickly on the surface, so as to resemble the 

 fruit of the horse-chestnut, (a, Fig. 102 and c, Fig. 104.) The projections, 

 seen in profile, give the corpuscles a stellate form, and those seen en face 

 appear as black dots. With acetic acid the corpuscles become globular and 

 pale, but their outlines remain distinct; with solutions of magenta they swell 

 up and assume a faint rose color, a dark-red spot appearing on some point 

 of their circumference. With (2 per cent.) solutions of Tannin, 2 after the 

 lapse of twenty or thirty seconds some point of the circumference of the red 

 corpuscle appears to give way, and a small button of highly retractile yel- 

 lowish-green substance projects, which sometimes contains a vesicular body 

 that may again be retracted into the corpuscle by the action of acetic acid. 

 The similar appearances produced by the action of a one per cent, solution 

 of Boracic acid on the red corpuscles of Reptilia have led Briicke 3 to regard 

 the Blood-corpuscles in these animals as consisting of a transparent shell or 

 case, the "cecoid," which is occupied by the "zooid," the latter being com- 

 posed of the nucleus and haemoglobin. If carbonic acid gas be transmitted 

 through a drop of blood which has been mingled with a little saline solu- 

 tion so that the corpuscles have become horse-chestnut shaped, the Stella; 

 disappear, and although there are many which do not reassume their natural 

 biconcave form, remaining saucer-shaped, yet their surfaces become smooth 

 and even. On the transmission of air they again become horse-chestnut 

 shaped, and this alternating effect may be repeated several times. Klein* 

 suggests that the action of Tannin and Boracic Acid is due to phenomena 

 of coagulation, and that of carbonic-acid gas to the resolution of a spontane- 

 ously coagulated constituent. Bile and Urea, according to Ku'hne, dissolve the 

 red blood-cells, though Jurasz 5 maintains that they only swell up and burst; 

 the addition of Urine seems to exert no other influence upon them than a 

 saline solution of equal density would do, as was long since ascertained by 

 Hewson. Alkalies cause the corpuscles to swell and to become cup-shaped, 

 after which they lose their color and disappear. The passage of a current 

 of electricity produced by the discharge of a Leydeu jar (having a surface 

 of 500 square centimetres) at intervals of from three to five minutes, causes 

 the circular disks to become slightly crenate, then rosette-shaped and horse- 

 chestnut-shaped; still later the processes are withdrawn and the corpuscles 

 become round and pale, giving up their coloring matter to the surrounding 

 fluid. 6 If blood be exposed to a temperature of 140 or 150 F., or if it be 

 frozen and then thawed once or twice, or if the whole of the gases be removed 

 by the air-pump, the corpuscles disappear, the coloring matter staining the 

 serum of a lake color, and only a few flocculi remain (Rollett). Professor 

 Lehmaun has remarked 7 that some of the red corpuscles resist the influence 

 of reagents much more than others do, and he infers that the latter are the 



1 A largo number of experiment? of this kind were made, and their results accu- 

 rately recorded, by Hewson (see his Inquiry into the Properties of the Blood, 178:2, and 

 his Description of the Kcd Particles of the Blood, 1788), who correctly drew from 

 them the inference of the vesicular character of the lied Corpuscles amongst the Pyr- 

 ciiieinata. See also the Lectures of Mr. Ancell on the Blond, in the Lancet for 1839; 

 the Memoir of Dr. G. O. Rees and Mr. S. Lane, in Guy's llosp. Kep., No. xiii ; and 

 the excellent Lectures by Mr. Gulliver, delivered at the College of Surgeons in 1862- 

 ;:;, in Mod. Times and Gazette. 



2 Roberts, Proceed, of Roy. Sue., vol. xii, 18(13, p. 481. 

 11 See his Vorlesungen iiber Physiolog., 1874, p. 73. 



4 Handbook to the Laboratory. 5 Inaug. Diss. Greifswalde 



6 Klein, op. oil., p. 17. See also Bottcher, Virchow's Archiv", Bd. xxxix, 18G7, n 

 4-27. 



7 Op. cit , vol. ii, pp. 184. 



