2 
THE YOUNG SCIENTIST. 
give to blood its chief peculiarities under 
the microscope. 
These characteristic specks have been 
called globules, discs, corpuscles and 
other names, but the term "corpuscle" 
is the one now generally adopted, as it 
conveys no statement as to the form of 
the object. The most curious thing about 
these corpuscles is that they differ greatly 
in size and shape in different animals, but 
are always nearly alike in different indi- 
viduals of the same species. Thus the 
blood of all human beings is nearly the 
same ; so is that of all horses, sheep, dogs, 
fish, frogs, etc., though the corpuscles of 
horses, fish ,and frogs differ greatly from 
HUMAN BLOOD COEPUSCLES. 
each other. In the plate forming our 
frontispiece we have collected a few of the 
most marked of these. First of all, the 
reader will observe that they differ in 
shape, the round corpuscles of No. 3, pre- 
senting a marked contrast to the oval 
ones shown in 4, 5, 6, 8, 10. As a general 
rule, the blood of animals which suckle 
their young (mammalia) are round, an ex- 
ample of this being the human blood 
shown at 3. On the other hand, corpus- 
cles from the blood of birds, fishes and 
reptiles are generally oval, as may easily 
be proved by the blood of a chicken or 
frog— two very easily procured animals. 
To this rule, however, there are some 
marked exceptions. Thus the blood cor- 
puscles of the camel, shown at 4, are 
elliptical, and the blood corpuscles of the 
loach— a little fish that is found in Eu- 
ropean waters— is round. 
The size too of the corpuscles varies 
greatly. Thus the blood of the proteus. 
No. 10, shows gigantic corpuscles nearly 
l-400th of an inch long, while the blood 
corpuscles of the musk deer are so small 
that it would take twelve thousand of 
them, laid side by side, to extend across 
one inch, and we have in our western 
waters an animal, the ampliiuma, with 
corpuscles even larger than those of the 
proteus. Both the proteus and the am- 
phiuma are allied to the frogs, but are 
hideous looking objects. 
Our readers will now easily understand 
how it is that microscopists can not only 
distinguish blood from most other liquids, 
but can distinguish the bloods of different 
animals from each other. Thus there 
would be no difficulty in distinguishing 
between the blood of the frog (No. 6) and 
that of a man (No. 3), and cases have 
arisen where this power on the part of 
microscopists has carried consternation 
to those who were not aware of it. Thus 
it is related that on one occasion a woman 
presented herself as an out-door patient 
at one of the London Hospitals, and de- 
sired to be treated for spitting of blood. 
The sputa, or spittle which she brought 
with her, was colored with blood, but the 
other symptoms did not tally with this 
one. The physician quietly made a mi- 
croscopic examination, and then asked 
her if feathers had yet begun to grow in 
any part of her body? She said "No." 
"That is very strange," said he, "for 
your blood has turned into chicken's 
blood, and your hair ought of course to 
turn into feathers." Seeing that her at- 
tempted deception had been detected, she 
confessed that she had killed a chicken 
and mixed its blood with her sputa, so as 
to convince the physician that she was 
sick, and then obtain, as out-door relief, 
those delicacies which such people need. 
Those who will compare Figures 3 and 5 
in our plate, will find no difficulty in see- 
ing how the physician detected the fraud. 
Another striking case in which the at- 
tempted palming, off of human blood for 
