3 66 THE POPULAR SCIENCE MONTHLY. 



explanation ; but am not, therefore, disposed to give up the riddle 

 without attempting a solution. 



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-jibrine, the material of the ultimate contractile fibers of the 

 muscle, is coagulated by boiling water, and further hardened by con- 

 tinuous boiling, in the same manner as albumen. Thus, the muscle- 

 fibers themselves and the lubricating liquor * in which they are im- 

 bedded must be simultaneously toughened by the method above 

 described, and this explains the pertinacious fibrosity of the result. 



But how is the apjDarent tenderness, the facile separation of the 

 fibers 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 fibers 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 or fasciculi are further enveloped in a j)roportionally stronger 

 sheath of similar membrane. All these binding membranes are mainly 

 composed of gelatine, or the substance which (as explained in No. 5) 

 produces gelatine 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 fibers, or fasciculi of fibers, that gives 

 to such overcooked meat its fictitious tenderness. 



I have entered into these anatomical and chemical details because 

 it is only by understanding them that the difference between true ten- 

 derness and spurious tenderness of stewed meat can be soundly under- 

 stood, especially in this country, where stewed meats are despised be- 

 cause 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. 



She proceeds, in accordance with this definition, when making an 

 Irish stew or similar dish, by " simmering " at 212 until, by the coag- 

 ulation and hardening of the albumen and syntonin, a leathery mass is 

 obtained ; then she continues the simmering until the gelatine of the 

 areolar tissue is dissolved, and the toughened fibers separate or become 

 readily separable. Having achieved this disintegration, she supposes 

 the meat to be tender, the fact being that the fibers individually are 

 tougher than they were at the leathery stage. The mischief is not 

 limited to the destruction of the flavor of the meat, but includes the 



* I have ventured to ascribe this lubricating function to the albumen which envelops 

 the fibers, though doubtful whether it is quite orthodox to do so. Its identity in compo- 

 sition with the synovial liquor of the joints and the necessity for such lubricant justify 

 this supposition. It may act as a nutrient fluid at the same time. 



