232 RALPH, ON THE EFFECTS OF 
been opened and has been kept undisturbed, and some organic 
matter be added, as blood or albuminous fluid, these starchy 
bodies will make their appearance. First of all a minute dot, 
resembling an oil-globule, will be seen, which, if steadily 
watched for a time, will be observed to increase in size, some- 
times attaining to that of an ordinary starch-grain, oval or 
rounded in form, and then it will assume a thicker consis- 
tence and solidify into a starch-grain, occasionally presenting 
a laminated structure, or a grooved line in the long axis of 
the oval form. 
Whenever these phenomena occur I have also noticed the 
appearance of the Prussian blue particles, and it appears to 
me that when prussic acid comes into contact with organic 
substances containing iron then a decomposition takes place, 
part of the iron combining with the cyanogen to form ferro- 
cyanic acid, and the remainder uniting with this ferrocyanic 
acid to constitute Prussian blue—that is, according to the 
accepted chemical views on this subject; the hydrogen 
liberated uniting with the carbow and oxygen of the organic 
substance, which has brought about this decomposition, to 
form the starch-grains. 
16. So, in lke manner, when the blood of an animal 
which has been killed or partially poisoned by means of 
prussic acid is examined by the aid of the microscope for 
the presence of Prussian blue particles, there may be seen, 
in very many instances, bodies which resemble these starch- 
grains, varying in size from below those of a blood-dise to 
four or five times one in extent. These, when acted on by 
iodine, may be seen to turn purple, and they also polarize. 
So, again, in those instances which I have noticed the 
presence of blue particles in the blood of patients, whether 
they have been taking prussic acid or not, I have frequently 
observed similar-looking bodies, and these tested with iodine 
have also reacted purple. . 
17. From all these observations I conclude that prussic 
acid is more or less neutralized in the blood by the iron 
present in it, and in proportion to the iron thus withdrawn 
there is so much starchy matter set free; whether the starch 
in this condition is prejudicial or harmless, owing to its 
semi-fluid condition, yet remains to be determined. 
18. The interest which attaches to the facts I have 
brought forward is not limited to chemical theories, or to 
our use of prussic acid as a remedial agent, but the facts 
observed may also serve to explain important points in 
physiology and pathology. I here briefly allude to some 
discoveries in pathological science, which relate to amyloid 
