ELATER 



413 



ELECTRIC UNITS 



. of the forms of peptone resulting from the gastric 

 digestion of elastin. 



Elater (el f -at-er) [k'/umip, a driver, hurler]. In biology, 

 (a) cne of the thread-like, usually spirally-coiled, 

 bodies found in the sporangia of mosses, liverworts, 

 and equisetum. They serve for the dispersion of spores. 

 lb) One of the free filaments of the capillitium of the 

 slime-moulds, (c) One of the elastic anal bristles of 

 the insect called spring-tail. 



Elaterin, or Elaterinum (el-at'-er-in, el-at-er-i' -num) 

 [h'/Arijpioc, driving away], C^H^O^ A neutral prin- 

 ciple obtained from Elaterium ecballium, or squirting 

 cucumber. It occurs in colorless, hexagonal prisms, 

 that are odorless and have a bitter taste. It is a power- 

 ful hydragogue cathartic. In toxic doses, it causes 

 emesis, spasmodic respiration, and death. Dose gr. 

 A— rV E., Pulv., Comp. (B. P.), contains elaterin I, 

 sugar of milk 39. Dose gr. j— v. E., Trituratio, 

 elaterin 10, sugar of milk 90 parts, thoroughly mixed. 

 Dose gr. ss-j. 



Elaterium (el-at-e* -re-um) \i7ja.-iipioq, driving away]. 

 A powerful hydragogue cathartic, being the dried sedi- 

 ment from the juice of the squirting cucumber, Ecba- 

 lium elaterium of Europe. Dose J-g gr. every two 

 hours ; of the tincture, gtt. x-xxx. 



Elbow (el' -bo) [ME., elbowe~\. The elbow-joint; the 

 articulation of the arm and forearm. That part of the 

 forearm and arm adjacent to the elbow-joint. E.- 

 jerk, one of the reflexes. See Reflexes, Table of . 



Elcoplasty (el' ' -ko-plas-te) . See Helcoplasty. 



Elcosis (el-k</-sis). See Helcosis. 



Elder (el'-der). See Sambucus. E., Dwarf. See 

 Ehvarf Elder. 



Elecampane (el-e-kam' -pan). See Inula. 



Election (e-lek' -shun) [electio, a choosing]. Selection 

 or choice, as of points (points of election) to be oper- 

 ated upon ; consideration of circumstances, such as age, 

 condition in life, occupation, sex, etc., in determining 

 whether to proceed with a proposed surgical operation 

 or not. Such operations are called Operations of Elec- 

 tion or of Complaisance. E., Triangle of, the Su- 

 perior Carotid Triangle. See Triangles, Table of. 



K\ectTepetST(e-lek-trep / -et-er) [fj/^tcrpov, amber ; rpi-eiv, 

 to turn]. An obsolete term for " commutator," a. v. 



Electric, or Electrical (e-lek* -trik, or e-lek' -trik-al) 

 [}/'/. ekt pov , amber]. Having the nature of or pro- 

 duced by electricity. E. Aura, a current of electri- 

 fied air. E. Brush, a wire brush used as an elec- 

 trode. E. Commutator, an instrument for automati- 

 cally interrupting or reversing the flow of an electric 

 current, making and breaking the same with desired 

 frequency. E. Chorea. See Dubinfs Disease. E. 

 Depilation, the permanent removal of hair from any 

 part of the body by the electrolytic destruction of the 

 hair-follicles. E. Discharger, the instrument that 

 directs the charge from a condenser through an ob- 

 ject. E. Endosmosis, cataphoresis. E. Fustiga- 

 tion, application of electricity through a metallic 

 brush. E. Head-bath, application of electricity by 

 means of an umbrella-shaped electrode surrounding 

 the head, but separated from it by a distance of from 

 one-half to one inch. E. Inertia, a term sometimes 

 employed instead of electro-magnetic inertia. E. 

 Insolation. See E. Sunstroke. E. Insulation, the 

 placing of non-conducting material with respect to a 

 conductor so as to prevent the loss of a charge or 

 the leakage of a current. E. Irritability, irritability 

 of nervous or muscular tissue to an electric discharge. 

 E. Megaloscope, an apparatus for the medical 

 exploration of the cavities of the body. E. Moxa, 

 bum made on the skin by electricity. E. Probe, 

 metallic conductor inserted into the track of a 



iex 

 I 



wound in order to ascertain the exact position of a 

 bullet, or other foreign metallic substance. E. Pros- 

 tration. See E. Sunstroke. E. Reactions, the 

 response of muscles and nerves to electric stimulation. 

 E. Shock, the physiologic shock produced in an 

 animal by an electric discharge. E. Shower-bath, a 

 device for general electrization ; one of the poles is 

 immersed in a tub containing an alkaline solution. 

 The patient stands beneath this reservoir on a metallic 

 stool connected with the other pole. The falling 

 water completes the circuit, dispersing the current 

 over the whole body. E. Sphygmograph, an instru- 

 ment for electrically recording the characters of the 

 pulse. E. Sterilization, sterilizing a solution by de- 

 priving it of whatever germs it may contain by means 

 of electric currents. E. Sunstroke, the physiologic 

 effects, similar to those produced by exposure to the 

 sun, experienced by those exposed for a long while to 

 the intense light and heat of the voltaic arc. E. Test, 

 the application of electricity to ascertain the exist- 

 ence or non-existence of central lesions after railway 

 injuries. It must be borne in mind that cutaneous 

 insensibility or absence of response in the muscles, is 

 not positive proof of organic lesion ; hence the so- 

 called electric test is not so absolutely relied upon as 

 formerly. 

 Electric Units. The lowest integral electric values. 

 They are as follows : — Ampere, the unit of measure- 

 ment of an electric current. It is the electro-motive 

 force of one volt produced in a circuit having one ohm 

 of resistance, equal to ^ C. G. S. electro-magnetic unit. 

 It is sufficient to deposit .3 grain of copper per minute 

 on the plate of a copper voltameter, or to decom- 

 pose sufficient acidulated water to generate 10.32 

 c. c. of mixed hydrogen and oxygen per minute. For 

 convenience the l0 1 ao part is used in medicine, name- 

 ly, the milliampere. This equals I volt divided by 

 1000. Ampere-hour, a unit of electric quantity 

 equal to one ampere flowing for one hour ; it is the 

 equivalent of 3600 coulombs. C. G. S. System, 

 Centimeter-gram-second Units, — the system of funda- 

 mental units in which a centimeter is adopted as 

 the unit of length, a gram as the unit of mass, and 

 a second as the unit of time. Coulomb, the unit of 

 measurement of electric quantity ; the quantity of 

 electricity that passes during one second through a 

 conductor having a resistance of one ohm, with one 

 volt of electromotive force. The micro-coulomb is the 

 millionth part of this amount. Unit of Current, a 

 conductor one cm. long which, if bent into an arc of 

 one cm. radius, will act with the force of one degree 

 on a unit magnet pole at the center. Dyne, the unit 

 of force ; i. e., the force which if it acted for one sec- 

 ond on a mass of one gram would, if the mass was 

 previously at rest, give it a velocity of one centimeter 

 per second ; or if it was previously in motion in the 

 direction of the force, would in that time alter its ve- 

 locity by that amount. Erg. See in it of Work. 

 Ergten, 10,000,000,000 ergs. Farad, the unit of 

 electric capacity. Practically, a capacity sufficient to 

 hold one coulomb of current having a potential of one 

 volt. The micro-farad, xTSwhujns P 31 * °f me meo " 

 retic farad, is commonly used. A practical form of 

 condenser of one farad capacity consists of 300 leaves 

 of tinfoil, each 16 centimeters in diameter, separated 

 by leaves of mica. The entire surface has an area of 

 about 1. 1 sq. meters. Joule, the unit of electric energy 

 or work. The volt coulomb. It equals 10,000,000 

 ergs. Unit Magnet Pole, a magnet having a strength 

 of pole sufficient to repel a similar pole at a distance 

 with a force of one degree. Megalerg, 1,000,000 

 ergs. Mega volt, 1,000,000 volts. Micro-coulomb. 



