288 
Liebig’s extract of meat. 
Gelatine does not belong to the composition of extract of meat, and mnst, 
therefore, be excluded as much as possible; it gives more consistency to the 
extract, and allows, to the detriment of buyers, of a larger percentage of 
water, and makes it liable to turn mouldy. But the action of tannic acid, as 
a reagent, might lead to erroneous conclusions, against which it is necessary 
to guard. 
In my little work ‘ On the Chemistry of Food ’ (Taylor and Walton, Lon¬ 
don, 1817), I say, p. 141: “ The portion of juice of the flesh which is soluble in 
cold water, but liot in alcohol, is precipitated by tannic acid; the precipitate 
softens like plaster in hot water, and cannot be distinguished from the tannate 
of gelatine, but it differs from gelatine by that characteristic property of 
both, that it does not gelatinize when concentrated.” Extract of meat, then, 
may and does precipitate with tannic acid, even when entirely free from 
gelatine. 
By the exclusion of gelatine, the yield in extract is naturally diminished. 
According to a recent communication received from Mr. Seekamp, 34 lbs. of 
fresh lean meat yield only 1 lb. of extract, as manufactured at Fray Bentos 
(corresponding with 45 to 48 lbs. of butchers’-meat, inclusive of fat and 
bones). 
It has been observed, that the colour and taste of the Fray Bentos Extract 
vary ; this is owing to the difference of sex and age of the animals. 
The meat of oxen always yields an extract of darker colour and stronger 
flavour, reminding somewhat of the flavour of fresh venison, pleasant when 
diluted; the extract of cows’ meat is of lighter colour, and a mild flavour, and 
is preferred by many persons. The meat of animals under four years cannot 
be used for the manufacture of extract; it yields a pappy extract of weak 
taste, like veal, and without flavour. 
According to the predominance of ox or cows’ meat, the colour and taste of 
extract varies, which is by no means a fault of the manufacturing x^rocess, and 
is fully explained by the preceding remarks. The extract of ox meat is, 
however, richer in creatinine and sarkin than the cows’ meat extract. 
The extract received from Munich, and examined by Messrs. Deane and 
Brady, was cows’ meat extract,—the Bavarian Pharmacopceia prescribing the 
use of cows’ meat, and not of ox meat. 
These gentlemen observe that they never experimented on a sam^fle which 
they had any reason to believe to be adulterated with chloride of sodium 
(common salt). My experience has taught me that such falsification, more 
especially by retail dealers, is by no means a rare occurrence, and it is even 
practised by manufacturers. 
I hold a sample of extract manufactured by Dr. Tenner, of Darmstadt, 
containing 9 jDor cent, of common salt, and, besides, 26 per cent, of water more 
than the Fray Bentos extract. He sells it in jars, with labels stating that the 
extract is ]3rex)ared “ according to Liebig’s process.” 
It is extremely difficult, as regards extracts of meat, the genuineness and 
purity of which are not discoverable by the eye, to protect the xDublic against 
fraud; all manufacturers prepare their extract according to what they call 
“Liebig’s x>i’ocess but since I have given only general, and not special, 
directions for manufacture, it so happens that every one fills in the details 
after his own fashion, and the consequence is that not one of these extracts 
is, m its composition, like another. 
There exist only ti\)o special directions for the manufacture of extract of 
meat, the one in the Bavarian Pharmacopoeia, the other in the Pharmacopoeia 
Gcrmanica, but these directions are not mine. 
I am. Sir, your obedient servant, 
J. v. Liebig. 
Munich, 22nd October, 186G. 
