Microscopical Society of Victoria. 5 
a coloured macula on the distended cell wall. The increased 
number of white corpuscles in the field of the microscope also 
points in the same direction, i.e., that their presence is due to the 
newly-formed red corpuscles retrograding to the white corpuscular 
stage, thus in a degree justifying us in referring the origin of the 
red from the white corpuscle. 
(8) We will now experiment more particularly on the red 
corpuscle. A solution of sulphate of copper must be made in 
ammonia, termed cupreate of ammonia. Place about a drachm of 
this solution in a test tube, and allow some fresh blood to flow 
into it to about the same amount, and agitate, and then examine 
the corpuscles under the microscope. Another method is to add 
a drop of blood as quickly as possible to a drop of the cupreate 
solution on the slide, and then proceed to examine it. Few white 
corpuscles will be seen; in all likelihood they will have been 
dissolved, but the red will be noticed under two or three forms. 
Some will be decidedly spherical, others plano-convex or bi¬ 
concave, and some few quite empty. Now, by cautiously 
adding magenta, all these corpuscles will take the dye and much 
more clearly exhibit their condition ; those which are half empty 
and bi-concave will show their contents, beautifully coloured, in a 
thick marginal ring, the central portion being quite clear, so that 
the light can be seen through it. The spherical ones also take 
colour and roll about, beautifully exhibiting tlioir distinctly 
globular form. 
This experiment gives us a very different result to the former, 
in which the magenta coloured the extruded material of the red 
corpuscles; but hero the cupreate prevents the outflow of their 
contents, and allows the ingress of the dye. If now water be 
gradually added, the cupreate is washed away, and with it the 
contained corpuscular matter is extruded, coloured. This experi¬ 
ment shows that when the blood is added directly from a vein to 
the cupreate solution, the corpuscles are arrested in their normal 
state; some of them, having parted with their contents in their 
transit through the blood vessels, are found half empty, while 
others being fully formed and having undergone no change, are 
preserved in their spherular form. By carefully drying off the 
fluid from the slide, the corpuscles can be preserved in oil for 
a time. 
