Reverting to what I have already said concerning the action of heat on the constituents of flesh, it is evident that in the first place the long exposure to the boiling point must harden the albumen. _Syntonin_, or _muscle-fibrin_, the material of the ultimate contractile fibres of the muscle, is coagulated by boiling water, and further hardened by continuous boiling, in the same manner as albumen. Thus the muscle-fibres themselves, and the lubricating liquor[10] in which they are imbedded, must be simultaneously toughened by the method above described, and this explains the pertinacious fibrosity of the result. But how is the apparent tenderness, the facile separation of the fibres of the same meat produced? A little further examination of the anatomy and chemistry of muscle will, I think, explain this quite satisfactorily. The ultimate fibres of the muscles are enveloped in a very delicate membrane; a bundle of these is again enveloped in a somewhat stronger membrane (_areolar tissue_); and a number of these bundles of _fasciculi_ are further enveloped in a proportionally stronger sheath of similar membrane. All these binding membranes are mainly composed of gelatin, or the substance which produces gelatin when boiled. The boiling that is necessary to drive out all the air from the tins is sufficient to dissolve this, and effect that easy separability of the muscular fibres, or fasciculi of fibres, that gives to such overcooked meat its fictitious tenderness. I am, however, doubtful whether _all_ the gelatin of these membranes is thus dissolved. The jelly existing in the tins shows that some is dissolved and hydrated, if my theory of the cookery is right; but there does not appear to be as much of this jelly as would be formed by the stewing of a corresponding quantity of meat at a lower temperature. Some of the membranous gelatin is, I suspect, dehydrated when the highest temperature of the process is attained—_i.e._ when the concentration of the juices raises the boiling point of their solution considerably above that of pure water. This, if I am right, would check further solution of the membrane, would hydrate and harden the remainder, and thus contribute to the hardening of the fibre above described. I have entered into these anatomical and chemical details because it is only by understanding them that the difference between true tenderness and spurious tenderness of stewed meat can be soundly understood, especially in this country, where stewed meats are despised because scientific stewing is practically and generally an unknown art. Ask an English cook the difference between boiled beef or mutton and stewed beef or mutton, and in ninety-nine cases out of a hundred her reply will be to the effect that stewed meat is that which has been boiled or simmered for a longer time than the boiled meat.