OPH 



291 



OPU 



tail ; eidos, form), an Order of 

 Echinodermata, which includes 

 the Brittle -stars, and the Sand- 

 stars. 



ophthalmia, n., df-thal'mi-ci (Gr. 

 ophthalmos, the eye), inflamma- 

 tion of any part of the eye, but 

 generally restricted to the con- 

 junction or thin mucous mem- 

 brane which covers the front 

 of the eyeball, and lines the 

 inner surfaces of the lids : oph- 

 thalmic, a., of'thcil'mik, pert, to 

 the eye : ophthalmoscope, n. , 

 of-tlial'-mo-skop (Gr. skopZo, I 

 view), an instrument for ex- 

 amining the interior of the 

 living eye. 



opiate, n. , op'-i'tit (L. opium, Gr. 

 opidn, opium, the juice of the 

 poppy), any preparation or 

 medicine for inducing sleep or 

 quiet, which contains opium : 

 opium, n., 6p''i"um, the concrete 

 milky juice, which speedily 

 hardens and becomes brown, 

 procured from the nearly ripe 

 capsules of Papaver somniferum, 

 and its varieties, Ord. Papaver- 

 acese ; a substance much used 

 in medicine as a narcotic or 

 anodyne. 



opisthocoalus, a., tip-isf'thd-sel'-us 

 (Gr. 8pisthen, behind ; koilos, 

 hollow), having the anterior 

 trunk vertebrae concave behind, 

 as in certain Crocodilia. 



opisthotonos, n., tiptfothti&tin-tis 

 (Gr. opisthe, backwards ; teino, 

 I draw or stretch), tetanic 

 spasms by which the whole body 

 is bent backwards. 



opium, see 'opiate.' 



opodeldoc, n., tip'tid'ffidfik (a 

 word coined by Paracelsus), the 

 soap liniment, consisting of hard 

 soap, camphor, rosemary, spirit, 

 and water. 



Opopanax, n., 8p>dp'.dn-aJcs (Gr. 

 opopanax from opos, juice ; 

 panax, the plant All-heal), a 

 genus of plants, Ord. Umbellif- 

 erse : Opopanax chironum, 



lar-on'-um (after Chiron, the 

 son of Saturn, one of the fathers 

 of medicine and botany), a plant, 

 so named from the supposed 

 virtue of the juice to cure all 

 diseases : opopanax, a gum-resin 

 procured from it, having a 

 peculiar and disagreeable odour. 



opponens pollicis, op'pon'&nz p6V- 

 lis'is (L. opponens t setting or 

 placing opposite ; pollex, the 

 thumb, pollicis, of the thumb), 

 the opposing muscle of the 

 thumb ; a muscle arising partly 

 from the annular ligament of the 

 wrist, and inserted into the 

 thumb, which brings the thumb 

 inwards as if to oppose the 

 fingers : opponens minimi digiti, 

 min'im-i didf-it-l (L. minimi, of 

 the least ; digitus, the finger, 

 digiti, of the finger), the opposing 

 muscle of the little finger ; a 

 muscle which moves the fifth 

 metacarpal bone forwards and 

 outwards, increasing thus the 

 cavity of the palm of the hand. 



optics, n. plu., opt'iks (Gr. optikos, 

 relating to sight from optomai, 

 I see), the science which treats of 

 everything that pertains to light 

 or vision, and the construction of 

 such instruments as telescopes, 

 microscopes, etc. , in which light 

 is the chief agent : optic, a., 

 dpt'ik, relating to the sight, or 

 the laws of vision ; visual : optic 

 nerves, the second pair of nerves 

 which proceed directly from the 

 brain, one to each eye, and are 

 the nerves of vision. 



Opuntia, n., tip-tin'-shi-a (from the 

 Opuntii, the inhabitants of anc. 

 Opus, a town, Locris, Greece, 

 where found), an interesting 

 genus of plants, Ord. Cactaceje, 

 commonly called ' Indian figs ' 

 or * prickly pears ' : Opuntia 

 cochinellifera, l6otsti4n<eUif-%r>& 

 (Sp. cochinilla, a wood - louse ; 

 L. fero, I bear), one of the 

 species on which the Coccus 

 Cacti, cochineal insect, feeds. 



