SCIENTIFIC SUMMARY. 
109 
pigment, and exhibits a striation which is sometimes transverse, sometimes 
longitudinal, and occasionally both ; but at this period there is no distinct 
line of demarcation between the striated and non-striated portion of the cell- 
contents, showing that the change takes place within the contents of the cell. 
The Extract of Meat. — Baron Liebig, who has favoured us with some admi- 
rable samples of this excellent preparation, has also forwarded to us a letter 
in which he very clearly explains what is the exact nutritive value of the 
ex tractum carnis : — “ The meat,” says the Baron, “ as it conies from the butcher, 
contains two different series of compounds. The first consists of the so-called 
albuminous principles (albumen, fibrin), and of glue-forming membrane. Of 
these, fibrin and albumen have a high nutritive power, although not if taken 
by themselves. The second series consists of crystallizable substances, viz., 
creatin, creatinin, sarcin, which are exclusively to be found in meat ; further, 
of non-crystallizable organic principles and salts (phosphate and chloride of 
potassium), which are not to be found elsewhere. All of these together are 
called the extractives of meat. To the second series of substances beef-tea 
owes its flavour and efficacy, the same being the case with the extradum 
carnis , which is, in fact, nothing but solid beef-tea — that is, beef-tea from 
which the water has been evaporated. Besides the substances already men- 
tioned, meat contains, as a non-essential constituent, a varying amount of 
fat. Now neither fibrin nor albumen is to be found in the ex tractum carnis 
which bears my name, and gelatine (glue) and fat are purposely excluded 
from it. In the preparation of the extract the albuminous principles are left 
in the residue. This residue, by the separation of all soluble principles, 
which are taken up in the extract, loses its nutritive power, and cannot be 
made an article of trade in any palatable form. Were it possible to furnsh 
the market at a reasonable price with a preparation of meat containing both 
the albuminous and extractive principles, such a preparation would have to 
be preferred to the ex tractum carnis, for it would contain all the nutritive 
constituents of the meat. But there is, I think, no prospect of this being 
realized.” These remarks show very clearly the actual value of the extract. 
It is, in fact, concentrated beef-tea ; but it is neither the equivalent of flesh 
on the one hand, nor an imperfectly nutritive substance on the other. It is 
never theless amost valuable preparation, and now commands an extensive 
sale in these countries and abroad • and it is, furthermore, the only valuable 
form in which the carcasses of South American cattle (heretofore thrown away 
as valueless) can be utilized. 
Engrafting Animal Tis sues . — In one of our numbers we recorded 
some of M. Bert’s experiments in this direction ; but one which he has 
recently reported is of still greater interest than any he has yet made known. 
It is briefly as follows : — The tail of a full-grown rat was separated from the 
body, and having been placed in a glass tube, was maintained at a tempera- 
ture of from 7° to 8° Centigrade for a period of seventy-two hours. It was 
then stripped of the membrane covering its base, and was inserted beneath 
the skin of another full-grown rat. Strange to say, it took root, and grew as 
perfectly from the back of the second rat as if it had been connected with 
its true proprietor. To prove that it was nourished in the proper manner, 
M. Bert killed the second rat three months after the operation, and injected 
coloured fluid into its aorta. Upon then examining the engrafted tail, he 
