120 ON THE CHEMICAL EFFECTS OF CHLORAL HYDRATE., ETC. 
eye of the observer the red molecule first pointed out by 
Dr. William Roberts, of Manchester, in 1863, and also 
brought further into notice by Professor Halford, in 1864, 
before the Australian Society.* My experiments with this 
agent, ammonio-sulphate of copper, go to show that, while 
the corpuscles are so acted on that they cannot pass out their 
contents, yet when magenta is applied this dye can pass in 
and colour them; and this coloration shows bv its tint the 
degree of emptiness or fulness of each corpuscle, proving that 
at the moment when the cupreous solution was added to the 
fresh-flowing blood the corpuscles were in different condi¬ 
tions, some perfectly full, while others were partially empty. 
By means of water the cupreous compound can be washed 
away, and then these same corpuscles are able to part with 
their contents, as they do under ordinary circumstances.f 
Subsequently I offered some observations on the action of 
snake poison on the blood, i. e. that it could be compared to 
that brought about by prussic acid; that this agent, while it 
attacks the iron in the blood, yet sets up a further action— 
that of causing the newly formed red corpuscles to retrograde, 
as it were, to the condition of the white. J 
Here are three important chemical agents, which have 
been applied to the blood in order to elicit information 
regarding either its structure or its chemical character, 
namely— 
Magenta ; which was first taken in hand, and which attacks 
the nuclei of the white corpuscles and colours them; also the 
granular matter exuded from the red. 
Ammonio-sulphate of Copper ; which prevents the egress of 
the solid portion of the red corpuscles; while at the same time 
magenta can pass in and colour them effectually. 
Prussic Acid; which lays hold of the iron in the blood, 
withdrawing it from some organic state of combination, 
giving rise also to the formation of corpora amylacea, or 
starchy bodies, by some further change effected on the blood 
constituents. 
I feel it is necessary thus to enter upon a resume of what 
has been done, in order that what follows may be rendered 
more clear, and that the minds of those to whom I address 
myself may be satisfied that all the following observations and 
experiments have proceeded gradatim , and owe their origin, 
and are connected, with my former labours in this field of 
observation. 
* ‘Australian Medical Journal/ vol. ix, 1864. 
f lb., vol. xi, 1866. 
f ‘Australian Medical Journal/ vol. xii 1867. 
