"and its whole chemical character, in the flesh of "animals so widely separated as the ox and the "crocodile, must be regarded as a fact worthy of "attention."

on flesh.

succeeds in

kreatine,

This is the essential part of all that is known from Results of preceding previous researches in regard to lactic acid and researches kreatine as ingredients of flesh. With respect to the other substances which are spoken of in chemical works as ingredients of flesh, I believe I need make no further quotations, since their intimate chemical relations are entirely unknown, and they offer no remarkable peculiarities beyond the facts that they are precipitated by acetate and subacetate of lead, by corrosive sublimate, tannic acid, or chloride of tin. In the early part of my investigation I succeeded, The author after many fruitless attempts, in obtaining a small obtaining quantity of kreatine from the juice of the flesh of fowls, and the study of its chemical relations soon showed, that this substance, during the evaporation of the fluid, loses its power of crystallising, in consequence of a change which it undergoes under the influence of the free acid present in the solution, and that in this way its purification and preparation are rendered much more difficult. The separation of the non-nitrogenised acid, which I soon found to be present in the juice of flesh, was at first attended with no small difficulties, and ultimately it is only the more exact acquaintance with the other substances occurring in this fluid, which has led to the simple methods of preparing and separating them,

and in de

vising sim

ple methods of obtaining the consti

tuents of

flesh.

Flesh extracted by

water.

Albumen and colour

ing matter

coagulated by heat.

The filtered liquid is

acid.

A good

to be described in the following pages in the order in which they present themselves to the observer.

When the finely minced flesh of newly-killed animals is extracted by water, there is obtained a red or reddish coloured fluid, having the taste which is peculiar to the blood of different classes of animals. If this fluid be heated in the water-bath, the albumen, as Berzelius has observed, coagulates first, and the liquid retains its red colour. The albumen at first separates as a nearly colourless coagulum, which afterwards collects in denser flocculent masses, and the colouring matter is only separated at a considerably higher temperature. It is easy to observe the point at which the albumen has been entirely coagulated, while the red colouring matter still remains in solution. It is now only necessary to bring the liquid into actual ebullition in a silver or porcelain vessel, in order to separate the whole of the colouring matter in the coagulated state, and we thus obtain a liquid easily filtered, which reddens litmus powerfully. The coagulated albumen, as well as the undissolved fibrine and cellular tissue, have also an acid reaction, which cannot be removed by washing with water. The insoluble residue of the flesh (fibrine, cellular tissue, &c.), when boiled with water, becomes opaque, milk-white, of horny hardness, and the water acquires by dissolving gelatine the property of gelatinising on cooling, when sufficiently concentrated.

If we desire to obtain the soluble constituents of

dispensable.

Small proportion of soluble

matter in

flesh.

the muscular substance without great loss, and with- press is inout using inconveniently large quantities of water, a good press is indispensable. We can, it is true, by the process I am about to describe, obtain with ease each of the substances mentioned, but to this end it is not advisable to operate on less than from 8 to 10 lbs. of flesh. It is only necessary to reflect that flesh contains from 76 to 79 per cent. of water, and from 2 to 3 per cent. of soluble albumen, and that after extraction with water there are left from 17 to 18 per cent. of fibrine and other insoluble matters, in order to perceive that even when we employ 10 lbs. and upwards of flesh we are still operating on comparatively small quantities of the soluble constituents. (On the average, the soluble matter of 10 lbs. of flesh, after the coagulation of the albumen and colouring matter, does not exceed 4 oz., and of this a very considerable proportion consists of inorganic salts, the phosphates being particularly abundant, while the remainder is formed of not less than five organic compounds.)

8

or 10 lbs. should be

of flesh

used.

of extrac

Supposing that 10 lbs. of flesh are to be operated Best mode upon, the half of this quantity is taken, and covered tion. with 5 lbs. of water. The mixture is carefully kneaded with the hands, and is then pressed as completely as possible in a bag of coarse linen. The pressed residue is a second time carefully kneaded with 5 lbs. of water, and again pressed. The fluid of the first pressing is set aside for further operations, that of the second being used for the first

Coagulation of the albumen

ing matter.

extraction of the second half of the flesh. In like manner the residue of the first half is a third time treated with 5 lbs. of water, and the expressed fluid serves for the second extraction of the second half, which is finally extracted a third time with pure water, in which it is allowed to soften, and again pressed out.

The united liquids are passed through a clean cloth to separate any fragments of muscular fibre, and colour and then introduced into a large glass globe, which is placed in a pan of water, the latter being gradually heated to the boiling point, and kept at this temperature till the liquid has lost its colour, and the whole of the albumen and colouring matter have separated in a coagulum. When a portion, heated to boiling in a test tube, remains clear, and deposits no flocculi, this operation is completed.

In many kinds of flesh, it is necessary, in order to separate the last traces of colouring matter after the coagulation of the albumen, to remove the liquid from the globe, and bring it into actual ebullition in a silver or porcelain vessel, which is so much the more easily done that the adhesion of the coagulum to the bottom of the vessel, where it would be singed or burnt, is no longer to be dreaded. It is moreover advisable, to remove all visible fat as be removed. completely as possible from the flesh, or to select

All visible

fat should

the flesh of lean animals, because the fat very much impedes both the extraction of the flesh with water and the pressing of the mass. When fat flesh is

used, the cloths or bags in which it is pressed become quickly useless, their pores being clogged with fat.

The liquid, after the coagulation of the albumen and colouring matter, is strained through a cloth, the coagulum pressed, and the united liquids

filtered.

The colour of the filtered liquid varies with the kind of flesh. That from flesh very full of blood, as is that of the ox, roe-deer, hare, and fox, has a reddish colour; while that from veal and fowl, as well as that from fish, is hardly coloured.

For the preparation of kreatine, the flesh of wild animals and of common fowls is the best adapted. The liquid obtained from these kinds of flesh is, when filtered, clear and limpid; that of the horse and of fish is always turbid; the taste of all is nearly the same, and the fluid from the flesh of the fox is in this respect not distinguishable from that derived from lean beef. The fluid from the flesh of the marten possesses a distinct musky smell, which becomes more decided when it is heated and evaporated.

All the different fluids obtained by the above process have an acid reaction, which appears to me the more worthy of notice, that, in the case of the ox, sheep, and game, it can only be obtained mixed with a proportionally large quantity of blood; and yet the alkali contained in the blood, on which its alkaline reaction depends, is yet not sufficient to

Characters

of the li

quid filtercoagulum.

ed from the

The liquid

is always

acid,