882 
mata, with the formation of numbers of minute evanescent 
globules, just as with chloroform. 
16. Effect of benzine.—Kssentially the same as that of 
chloroform and carbon disulphide. 
17. Effect of turpentine-oil.—FKssentially the same as, but 
less vigorous than, chloroform on carbon disulphide. When 
the turpentine oil was added in the liquid form to the cor- 
puscles the formation of the numerous fine globules was not 
obtained, and the stromata were not dissolved. ‘Turpentine 
spirit may have a more vigorous action. 
18. Eiffect of solution of acetate of rosanilin and of tannin 
(Roberts’ experiments).—As discovered by Dr. Roberts, of 
Manchester (loc. cit.), magenta dye, when allowed to act on 
either human or frog’s red blood-corpuscles (also those of 
other vertebrates), causes a discharge of the htemoglobin, and 
(colouring the nucleus deep red in the latter case) produces 
a well-marked red “macula,” more or less oblong on the 
wall of the corpuscle. Tannin, on the other hand, causes a 
sharp little pullulation in the wall of the corpuscle, at the 
same time granulating the nucleus. In the human corpuscle 
Roberts found that there was rarely more than one such 
macula or pullulation ; in the frog often two, three, or more. 
I have repeated Roberts’ experiments, using a nearly saturated 
solution of the reagent in each case. In figs. 22, 25, 24, the 
results are depicted. The macula and the pullulation are due 
to something entirely distinct from what we have had evidence 
of in the action of the reagents hitherto considered. When 
the red corpuscles of the frog are mixed on a glass slide with 
a little of the magenta solution, and examined, they are 
found to have become small and spherical, as under the action 
of ammonia. ‘The nucleus is rounded and sometimes granu- 
lated, sometimes not so, whilst the body is faintly stained or 
colourless. The outline or wall of the corpuscle looks 
thicker than under other circumstances, and one, or as many 
as four, points are seen in the circumference of the corpuscle 
deeply stained, like the nucleus (fig. 23). Besides this, very 
generally round each corpuscle, and more especially near the 
stained points or ‘‘ maculz,” deeply stained granular matter 
is seen in the plasma. By allowing the magenta slowly to 
come in contact with the blood, whilst the slide was on the 
microscope stage, I was able, after many trials, to watch one 
corpuscle through its changes. The corpuscle first shortened 
and became nearly spherical (fig. 23 a, 4), and then dis- 
charged its colouring matter. It then took a very slight pink 
tint from the magenta fluid (fig. 23 c), and next, suddenly 
the nucleus, which had previously been indistinct, assumed 
