I 



PETECHIAL 



1057 



PETROLIN 



skin, but is of a reddish or purple shade, and does not 

 alter on pressure by the finger. 

 Petechial pt te'-ke-al) [It. , peteche •, flea-bite]. Char- 

 ged by or of the nature of petechise. P. Fever, 

 nytn of Fever, Cerebrospinal, and of Fever, 

 'tus. P. Scurvy. Synonym of Purpura sim- 



Petechianosis (pe-te-he-an-o / -sis). Synonym of Pe- 



Petechiate [pe-te , -ke-al) [lt.,petecchia, aspot]. Having 

 petechia ; spotted. 



Petersen's Bag. A rubber bag with a capacity of 

 about 15 ounces, to be inserted into the rectum and 

 then distended, so as to elevate the bladder in the 

 operation of supra-pubic cystotomy. 



Petiolaceous [pet-e-o-la'-se-us). Same as Petiolate. 



Petiolar I pet* '-e-o-lar) [petiolus, a petiole]. In biology, 

 belonging to a petiole or attached to one. 



Petiolary [pet'-e-o-la-re). Same as Petiolar. 



Petiolate | pef-e-o-lat) [petiolus, a petiole]. In biology, 

 -essing a petiole; mounted upon a foot-stalk, or 

 peduncle. 



D etiole [pet'-e-ol) [petiolus, a stem, or stalk of fruits]. 

 In biology: (1) A leaf-stalk or foot-stalk. (2) The 

 ; slender part of a wasp or ant, joining the thorax and 

 l abdomen. 



Petiolulate 1 pet'-e-o-lu-lat) [petiolulus, petiolulus]. In 

 I biology, mounted upon a little leaf-stalk of its own ; 

 applied to a leaflet or foliole. 



Petiolule [peP-e-o-lul) [petiolulus, dim. of petiolus, 

 petiole]. In biology, a small leaf-stalk, such as 

 those of the leaflets or folioles of compound leaves. 

 P. epiglottidis, the narrow, attached, stalk-like por- 

 tion of the epiglottis. 



D etiolus [pet-i' -o-lus) [petiolus, a stem or stalk of 

 fruit: //., Petioli\ In biology, a stem, stalk, or 

 petiole ; as the petiolus of the epiglottis. 



'etiotization [pet-e-o-tiz-a' -shun). A method of im- 

 proving wines by adding sugar and water to the marc 

 from which the juice has been separated, and ferment- 

 ing again. The process may be repeated several 

 times, the different infusions being mixed. 



J etit, Canal of (pet-e'). The narrow annular cleft, tri- 

 angular in section, bounded in front by the zone of Zinn, 

 mesially by the crystalline lens, and behind by the sub- 

 stance of the vitreous body in the eye. See Canal. P.'s 

 Hernia. See Hernia. P.'s Operation, an operation 

 for the relief of strangulated hernia. It consists in a 

 division of the stricture without opening the sac. See 

 Operations, Table of. P., Triangle of. See Triangles, 



;tit Mai [pet-e* '-mal) [Fr.]. See Epilepsy. 

 etiveria pet-iv-e' '-re-ah) [after J. Petiver, a London 

 apothecary]. A genus of phytolaccaceous plants, 

 growing in tropical America and Africa. P. alliacea, 

 ot the West Indies and Guinea, is stimulant, diuretic, 

 sudorific, anodyne, and depurative. P. tetandra, of 

 Brazil, has similar uses. Its tincture has been recom- 

 mended for external use after baths, and as a local 

 stimulant in paralysis. L'nof. 



etri's Capsules, Dishes, Plates, or Saucers. Re- 

 ceptacles for cultures in bacteriologic investigation ; 

 shallow cylindric covered glass vessels, in which the 

 colonies may be counted without removing the cover. 

 P.'s Sand-filter, a small filter used in the bacteriologic 

 examination of air. A glass tube, 9 centimeters long, 

 j is provided with two portions of sand (previously 

 I through a sieve with meshes 0.25 millimeter 

 wide) each 3 cm. long, and 0.5 cm. apart, little plates 

 ■ 'v^ raSS gaUZC kee P' n S tne portions in position. The 

 ; tube and its contents, the end having been plugged 

 with cotton, are sterilized in an oven, at iqo C. A 

 67 



rubber stopper, through which passes a glass tube, is 

 then fitted into one end of the tube, and the apparatus 

 is connected with an aspirator of known capacity. 



Petricolous [pet-rik* '-o-lus) [xirpa, rock; colere, to in- 

 habit]. In biology, inhabiting rocks. 



Petrifaction ( pet- rif-ak' -shun) [ttst/m, a stone ; facere, 

 to make]. The condition resembling stone-calcifica- 

 tion. In obstetrics, conversion of the fetus into a 

 lithopedion. Petrifaction of tissues is brought about 

 by the deposit in them of salts of lime and magnesium. 



Petrissage [pa-tre-sahzh') [Fr., kneading]. A form 

 of "soft attachment," in massage, the hand of the 

 operator " climbing " like a caterpillar. 



Petrobasilar (pet-ro-baz'-il-ar) [-irpa, stone; 3aaic, 

 base]. Pertaining to the petrous portion of the tem- 

 poral bone and the basilar portion of the occipital 

 bone. 



Petroccipital [pet-rok-sip* '-it-al). Synonym of Petro- 

 occipital. 



Petrohyoid ( pet - ro - hi' '- old ') [— erpa, a rock; voetdr/c, 

 shaped like the letter upsilon]. Related to the hyoid 

 bone and- the petrous portion of the temporal bone. 

 P. Muscle, a muscle of some batrachians. 



Petrolardium (pet-ro-lar'-de-um). Synonym of Petro- 

 latum. 



Petrolatum (pet-ro-la* -turn) [-erpa, rock; oleum, oil]. 

 Petroleum ointment ; Cosmolin. A jelly-like prepa- 

 ration obtained from the residium of petroleum, sol- 

 uble in ether, insoluble in water and alcohol, and known 

 commercially as vaselin and as cosmolin. It is an ex- 

 cellent basis for ointments and a valuable emollient. P. 

 molle, soft petrolatum. P. spissum, hard petrolatum. 



Petrolene (peP-ro-len) [rrerpa, rock ; oleum, oil]. A 

 liquid hydrocarbon mixture obtained from petroleum. 



Petroleum (pet-r</-/e-um) [irrrpa, rock ; oleum, oil]. 

 Rock-oil; Naphtha; probably a product of the dry- 

 distillation of coal-beds caused by the earth's heat ; or 

 of the dry distillation of the fatty constituents of fossil 

 organisms. In a crude condition, it is a thick, oily 

 liquid, of brownish color, with greenish luster. On 

 exposure to air, its more volatile constituents are lost ; 

 it then thickens and passes into asphaltum. P., 

 American, consists almost exclusively of normal paraf- 

 fins. In a crude form, it has a specific gravity of from 

 0.8 to 0.92, and distils over at from 300 to 360 C. and 

 beyond this. P. Benzine (not to be confounded 

 with the benzene of coal-tar), a product of petroleum 

 obtained by fractional distillation ; it has a specific 

 gravity of from 0.68 to 0.72, and distils at from 70 

 to 90 C. , and consists of hexane and heptane. P., 

 Caucasian (from Baker), has a higher specific gravity 

 than American petroleum ; it contains less of the light 

 volatile constituents and distils at about 150 C. P. 

 Ether, a product of petroleum obtained by fractional 

 distillation; it has a specific gravity of from 0.665 to 

 0.67, distilling at from 50 to 6o° C. ; it consists of 

 pentane and hexane. P., Galician ; in composition, 

 intermediate in position between American and Cau- 

 casian petroleum. P. gelatum, petrolatum. P., 

 German, contains benzene hydrocarbons, but consists 

 chiefly of the saturated hydrocarbons and naphthenes. 

 P. Oil, Light, a liquid resembling P. Benzine, having 

 a specific gravity of o.70oro.7i. P., Refined; Kero- 

 sene ; a product of petroleum by fractional distillation ; 

 it boils at from 150 to 300° C, and has a specific 

 gravity of from 0.78 to 0.82. P. Spirit. Synonym 

 of Benzine. 



Petroliferous (pet-ro-lif'-er-us) [-erpa, rock ; oleum, 

 oil ; ferre, to bear]. Producing petroleum. 



Petrolin [peP -ro-lin) [-erpa, a rock ; oleum, oil]. The 

 commercial name for a combination of hydrocarbons 

 derived from petroleum. 



