unit

(u’nit) [L. u’nus one]. 1. A single thing. 2. A quantity a umed as a standard of measurement. amboceptor u., the least quantity of amboceptor with which a definite amount of red blood-corpuscles will be di olved by an exce of complement. Angstrim’s u., one-ten-thousandth of a micron. antigen u., the least quantity of antigen which will fix one unit of complement so as to prevent hemolysis. antitoxic u., a unit for expre ing the strength of an antitoxin. It is the amount of antitoxin required to neutralize 100 times the quantity of the standard toxin that is sufficient to kill a guinea-pig weighing 250 gm. Called also immuntsing u. u. of capacity. See farad. C. G. 8. u., any unit in the centimeter-gram-second system. complement u., the least quantity of complement which will hemolyze a definite amount of red blood-corpuscles in the presence of an amboceptor unit. u. of current. See ampere. u. of electricity. See amperc, coulomb, farad, ohm, volt, and watt. u. of electromotive force. See voll. u. of force. See dyne. u. of heat, the quantity of heat required to raise a kilogram of water one degree centigrade. See calorie and therm. hemolytic u., the amount of inactivated immune serum, which, in the presence of complement, will completely hemolyze 1 c.c. of a ς per cent. emulsion of washed red blood-corpuscles. immunizing u. See antitoxic u. mache u., a unit of emanation, being that quantity which produces a current of saturation equal to one-ten-thousandth of the electrostatic unit of current intensity. pepsin u.,a unit for measuring the proportion of pepsin in the gastric juice. u. of quantity. See coulomb. u.of resistance. Sce ohm. toxic u., toxin u., the smallest dose of a toxin which will kill a guinea-pig weighing about 250 gm. in from three to four days. urotoxic u., the smallest quantity of urotoxin which will kill an animal weighing 1 gm.