194 ANNUAL OF SCIENTIFIC DISCOVERY. 



tain, they contribute much to the animal's thrift. The apples should 

 be ripe or nearly so, and of palatable kinds ; sour apples, when fed 

 in a raw state, are not relished much by animals, but by cooking with 

 meal they are as equally well received as the sweet varieties. Recent 

 chemical analyses by Mr. J. H. Salisbury, of Albany, show that good 

 varieties of the apple are richer in those bodies which strictly go to 

 nourish the system than potatoes are, or, in other words, to form 

 muscle, brain, nerve, and in short assist in sustaining and building up 

 the organic part of all the tissues of the animal body. Albany Culti- 

 vator, Sept. 



THE FIBRINE OF MUSCULAR FIBRE. 



WHEN finely divided flesh is freed, by exhaustion with cold water 

 and pressure, from matters soluble in this menstruum, a white taste- 

 less residue is left, which consists of true muscular fibre, nerves, and 

 cellular tissue. Muscular fibre is usually considered to be identical 

 with the fibrine of blood ; but this is an error, which has probably 

 arisen from their similarity in physical properties. When the fibrine 

 of the blood is immersed in water containing one tenth part of muri- 

 atic acid, in a short time it swells into a gelatinous mass ; on the ad- 

 dition of a stronger acid, the jelly contracts nearly to its original 

 volume, and again swells in water like a sponge. This experiment 

 may be repeated several times without any perceptible quantity of 

 the fibrine becoming dissolved in the liquid. The fibrine of muscular 

 fibre is quite different in this respect. When placed in water con- 

 taining the above amount of acid, the greater portion dissolves imme- 

 diately and perfectly, forming a liquid which is slightly turbid from 

 the presence of fatty matters, and which is with difficulty separated 

 completely from the undissolved portions by filtration, although this 

 may be perfectly effected. This solution takes place at ordinary tem- 

 peratures. The solution coagulates when neutralized, forming a thick, 

 white, gelatinous paste, readily soluble in excess of alkalies. The 

 precipitate obtained on neutralizing the muriatic acid of the fibrine 

 of muscle is soluble in lime-water, and the solution, when boiled, yields 

 a coagulum like a dilute solution of albumen. If the precipitate has 

 been previously boiled with water, it is insoluble in lime-water. But 

 the most curious fact is, that this constituent of muscle, which is so 

 readily dissolved in muriatic acid, exists in very different proportions 

 in different kinds of animals. Thus, the muscular fibre of poultry 

 and oxen is almost entirely soluble, whilst, in the case of the muscular 

 substance of sheep, more than one half, and in that of the calf far 

 more than this proportion, remains undissolved. This insoluble resi- 

 due is elastic and white ; but it is more gelatinous and softer than the 

 fibrine of blood which has become swollen in slightly acidulated water. 

 The fibrine of muscle especially differs from that of blood in the 

 amount of nitrogen contained in it, and approximates to that of albu- 

 men. The fibrine constitutes only a fractional portion of 1 per cent, 

 of the blood ; in accordance with those analyses which are most to be 

 depended on, it contains more nitrogen than the fibrine of muscle, 



