40 CELLULAR STRUCTURE OF THE RED BLOOD-CORPUSCLES. 
inch; but previous to that the globules, having a magnitude 
of from *010 to ’01 1 of a millimetre, possess a little round 
granular nucleus. In all the oviparous vertebrates the glo¬ 
bule, whatever its form, encloses a colourless spherical or 
oval nucleus, insoluble in water and acetic acid, while the 
red mass is soluble in these menstrua/ 5 
In the course of some researches of my own, however, 
“ On the Detection of Red and White Corpuscles in Blood 
Stains, 55 * I have shown, first, that if a few 7 drops of fresh 
blood be stirred up in many times its bulk of pure w 7 ater, 
the coloured hsemato-crystallin will be dissolved, while a 
whitish insoluble residue, found under the microscope to be 
composed of transparent hyaline spheres about ^—--^th °f an 
inch in diameter, subsides to the bottom of the vessel; 
secondly, that if a fragment of dried blood-clot is exposed 
to the action of a current of fresh water, the haemato-crys- 
tallin will, after a few minutes, be washed away, leaving an 
aggregation of what appear to be similar delicate cells, altered 
in shape by mutual pressure, but still preserving much of 
their rounded contour; and thirdly, by a calculation of the 
superficial area of the human red blood disk, based upon 
accurate measurements of its dimensions when magnified 
nearly 1800 times, that supposing a cell wall to exist, there 
would be almost precisely enough membrane contained in 
it to cover the surface of a sphere having the exact diameter 
of the red corpuscles when rendered globular by the action 
of water. 
In one of my experiments on the action of water upon 
blood, as detailed in that paper, the development of Bacteria 
so obscured these supposed membranous cell walls that they 
became unrecognisable after standing seventy-two hours, so 
that, in order to determine whether their apparent insolubility 
could be overcome by prolonged maceration, I made the 
following additional investigations :— 
On the 24th of March, 1870, I thoroughly stirred two 
fluid drachms of blood into two fluid ounces of fresh water, 
and allowed the mixture to stand undisturbed for forty-eight 
hours, w 7 hen a light and flocculent deposit of a pale pink 
colour, occupying about half a fluid-ounce of the liquid, 
had fallen to the bottom of the vessel. On examination 
under the -Vinch objective, this was found to be chiefly com¬ 
posed of very transparent spherical bodies, about T3 Voth of 
an inch in diameter, which became beautifully distinct and 
quite visible with an ordinary J-inch when tinted by a minute 
portion of aniline solution introduced at the margin of the 
# ‘Am, Jour, of Med, Sciences/ July, 1869. 
