Page:The New International Encyclopædia 1st ed. v. 14.djvu/190

MUSCLE SENSE. 134 MUSCULAR FORCE. from the articular surfaces. It plays a large part in the perceptions of weight, resistance, etc.. enters into the fatigue-complex of exhaust- ing bodily cxenise, and occurs in muscular cramp, its variations do not necessarily run parallel to the variations of the muscular sen- sation, for very ditferent degrees of muscular contraction are. obviously, compatible with one and the same amount of pull upon the tendons. Consult: Goldscheiiler. Gcsamnielte Abhandlun- gen, vol. ii. (Leii)zig. 181)8) ; Bastian, The Brain as an Organ of ^lind (London, 1885) ; Henri, in Anni'c psychologiquc, vol. v. (I'aris. 180!)); Titchcner, Experimental Psychology, vol. i. (Xew York. llMJl). MUSCOGEE, mus-ko'j*. A town of the Creek Nation. Indian Territory. 154 miles north by east of Fort Worth, Tex., on the Missouri, Kansas and Texas Railroad (Jlap: Indian Territorv. H 3). It is the seat of the Harry Kendall Col- lege (Presbyterian), oi)ened in 18!)4. and is the headquarters of the Inited States agent for the Indians. The town is the commercial centre for extensive agricultural and stock-raising districts. Population, in I!)00. 42.)4. MUS'COVITE. A mineral aluminum-potas- sium silicate that crystallizes in the monoclinic system, and is the most common nu'ml>er of the mica group. Its usiuil color ranges from gray to brouTi. but it also occurs in dill'erent shades of green, violet, yellow, and sometimes rose-red. It has a vitreous lustre that is more or less pearly or silky, and its specific gravity is from 2.7G to .3. Muscovite is one of the essential con- stituents of granite, gneiss, mica-schist, and cer- tain other rocks. It is widelydistributcd in nature, occurring most al>uncliuitly in Tyrol. Styria. on the Saint (iotthard. and eNewhcre in Switzer- land, as well as at I'aris. Me., (irafton, X. H., Chesterfield. Mass.. an<l numerous localities of North Carolina, in the United States. The fact that it has a cleavage parallel to the base, and is easily separated, forming thin elastic plates which are transparent to translucent, led to its use as the material for window])anes in Russia, whence its name of Miixcoiy filasx. and to its extensive and similar use in stoves mider the name of "isinglass.' It is also employed com- meriially in wall ])aper, as a filler, in electrical ma<'hines as an insulator, and to a certain extent as a paint. See Mlf.^. MUS'COVY. A name formerly applied to Rus- sia. «ho>H capital down to the beginning of the eighteenth century was Moscow. The word is still used in ornate style. MUSCOVY DUCK (cnrrupled from munk- aurl,). . large South .American duck {Cairina moxrhiitd) in which the male is much larger than the female, and has lleshy wattles on the fore- head and lores, and a crest of long feathers. This duck has long been doniesti<'ated in Brazil anil in Kurope. where it is especially in favor in (Jennany. In this country they are less esteemed, because of their (luarrelsome nature and ability to harm one another or their com- panions In the poultry yard. Two varieties are recognized, 'roloreil' and 'white.' which are thus described in Ilowanl's I'lirwrrs' Hiillitiii. .Yo. (i^, of the Inited States Hepartnient of .griculture (Washington. 1S!)7): The head of the colored nuiseovy is glossy black and white: the bill is dark-horn in color; eves, brown; the back in i color of plumage is lustrous IjIuc black, which is , sometimes broken with white; the color of the breast and body is the same as that of the back, i 1 he wing coverts are rich, lustrous green black, I and the tail feathers may be either black or ( white, the latter being preferred. The thighs, like the tail feathers, may be either black or white, white being preferred; the shanks, toes, and webs vary in colm- from yellow to dark lead or black. The white muscovy in color of plum- age is pure white throughout: feathers of any other color will disqualify the bird for show purposes. The eyes in the white variety are of 1 a leaden-blue or gray color, while those of the ' colored are brown. The shanks, toes, and webs • are of a pale-orange or yellow color. The stand- ' ard weight of the adult drake is ten pounds; i adult duck, eight pounds. The flesh is good and | loses in cooking tlie uuisky odor of the living bird. 1 MUSCULAR FORCE, Origin of. This sub- ■ ject has occupied the attention of physiologists for many years, and numerous theories have been offered to explain the phenomena of nuiscular , energy. The older observers, represented by '^ Liebig. held that nitrogenous food went to build 'i up and maintain muscular tifisue and that i energy was evolved in the splitting up (or oxida- tion) of this class of food, the waste lieing repre- sented in the excreted urea. The non-nil rugenous foods (carbohydrates or starches, and fats), onTj the other hand, were supposed to be entirely de-k voted to the production of heat. Muscular work? should therefore cause a distinct increase in the J elimination of urea. But this theory is invali- f dated liy the fact that the excretion of urea does* not keep jiace with the production of energj'. Later observers have taken the opposite view, ■ that force is generated by the oxidation of non- i nitrogenous substances. and that the nitrogen con- stituents of muscle are rather to be looked upon 4 as forming a part of the machine in which the ^ former substances are burned than, as con- ■' stituting the fuel themselves. ,' It has been suggested by Herman that nuiscular i activity depends upon the splitting up and sub- I sequent re-formaticm of a complex nitrogenous I body which he calls inogen. From the deconi- f position of this liody there result carl)on dioxide, sarcolactic acid, and a gelatino-alliuminous body. Of these the earlion dioxide is carried away by the blood, and the acid and the albumincuis substance, j at least in part, go to rebuild the inogen. The other materials of which the inogen is formed are supplied by the blood. Of tliese materials f^ oxygen and some carbohydrate substance form a " part. The decomposition takes i>lace both in resting and active muscle, but is much greater in the latter. This theory explains certain known facts of muscular metabolism; first, that nuiscle absorbs oxygen and gives otf carlum dioxi<lc dur- ing both rest and activity, and that increased exchange of these gases takes place during the latter condition: that this process is atteiid(>'d by the i)roduition of heat; and that uuiscle during rest produces nitrogenous crystallizable sub- stances such as krealin from the nietaboli.sm go- ing on constantly during life. For a full discussion of this subject, see Foster, Tr.Tthoolc of I'hy.iiology (Xew York, lllOD), and Kirke. Uandhook of Phgsiology (Philadelphia, 11IIJ2). See also article Physi OLOQY.