DIOPTRAL 



376 



DIPHYCERCAL 



Dioptral (di-op' -tral) [dioirryp, a watchman]. Pertain- 

 ing to a dioptry ; expressed in dioptrics. 



Dioptre {di-op' -ter). See Dioptry. 



Dioptric [di-op' -trik) [did, through; bipecdai, to see]. 

 I. Pertaining to transmitted and refracted light. 2. 

 A dioptry. 



Dioptrics {di-op' -triks) [did, through ; brpeadai, to see]. 

 A branch of optics treating of the refraction of light 

 by transparent media, especially by the media of the 

 eye. 



Dioptry (di-op' -tre) [did, through ; btpeadac, to see]. 

 The most commonly accepted unit of measurement 

 for optic lenses. A positive (or plus) spherical (bi- 

 convex) lens of one dioptry has a focal distance of one 

 meter ; one of two dioptries, a focal distance of one- 

 half a meter, etc. See Lenses, and Spectacle-lenses. 



Diorthosis (di-or' -tho-sis) [Sid, throughout ; bpddeiv, to 

 straighten]. The surgical correction of a deformity, 

 or repair of an injury done to a limb. 



Diorthotic [di-or-thot'-ik) [did, throughout; 6p66eiv, to 

 straighten]. Relating to or effecting a diorthosis. 



Dioscorea (di-os-ko' -re-ah) [Dioscorides, a famous 

 Greek physician and botanist]. Wild Yam, Colic 

 Root. The rhizome of D. villosa, a creeping-plant, 

 indigenous to the eastern U.S. It is claimed to be ex- 

 pectorant, diaphoretic, and stimulant to the intestinal 

 canal, in large doses causing neuralgic pains and 

 erotic excitement. It is used successfully for bilious 

 colic. D., Fid. Ext., of standard strength, dose 

 Tt^xv-xxx. Unof. 



Dioscorein (di-os-ko' -re-iti) [Dioscorides, a Greek bot- 

 anist]. A precipitate from a tincture of the root of 

 Dioscorea villosa. It is antispasmodic, expectorant, 

 and diaphoretic. Dose ]/ 2 to 4 grains. Unof. 



Diosma (di-oz'-mah) [diog, divine ; oc/i^, odor]. Buchu. 

 See Barosma. 



Diosmin (di-oz'-min) [diog, divine ; bdfirj, odor]. An 

 active principle obtained from various species of Buchu. 

 It is an amorphous, bitter substance. Unof. 



Diosmosis (di-os-mo'-sis). Same as Osmosis. 



Diotic (di-ot'-ik) [dig, two; ovg, urdg, ear]. Binaural ; 

 pertaining to both ears. 



Dioxid (di-oks'-id) [dig, two; bt-vg, sharp]. An oxid 

 containing two atoms of oxygen and one of a metal. 



Dipentene [di-pen' -ten) , C 10 H 16 . Cinene ; a compound 

 produced by heating pinene, camphor, and limonene 

 to 250— 300 C. It is present in the Russian and 

 Swedish turpentine oil. It is a liquid with an agree- 

 able lemon-like odor; sp. gr. 0.853; boils at 175— 

 176° C. 



Dipetalous (di-pef -al-us) [dig, two; Trtrahov, a leaf]. 

 In biology, two-petaled. 



Diphenyl [di-fen'-il) [dig, two; tyoivi!-, purple-red], C 12 - 

 H 10 . A hydrocarbon resulting from the action of sodium 

 upon the solution of brom-benzene in ether or benzene. 

 It is also present in coal-tar. It crystallizes from alcohol 

 and ether in large colorless leaflets, melting at 71 C. , 

 and boiling at 254 C. D. -methane, Cj 8 H,j. Benzyl 

 benzene ; a hydrocarbon obtained from benzyl chlorid 

 and benzene. It is easily soluble in alcohol and ether, 

 possesses the odor of oranges, crystallizes in needles, 

 melts at 26. 5 C, and boils at 262 C. 



Diphenylamin (difen-W -am-in) [diphenyl ; amin\, 

 C 12 H U N. A compound produced in the dry distilla- 

 tion of triphenyl rosanilin (Rosanilin blue) ; it is also 

 prepared by heating anilin hydrochlorid and anilin to 

 240 . It is a pleasant-smelling, crystalline compound, 

 melting at 54 and boiling at 310 . It is almost in- 

 soluble in water, but readily soluble in alcohol and 

 ether. It serves in the preparation of various dye- 

 stuffs. D. Orange. See Pigments, Conspectus of. 



Diphenylol (di-fen'-il-ol), C, 2 H 10 O. Oxy-diphenyl ; 



obtained by diazotizing amido diphenyl sulphate. It 

 sublimes in shining leaflets, melting at 165 C, and 

 boiling at 305. 8° C. 



Diphosphatid [di-fos' -fat-id) [di, twice ; phosphorus']. 

 Any phosphatid containing the phosphorized radical 

 twice (such as assurin). Diphosphatids exist in the 

 brain-substance and in other animal tissues. 



Diphtheria (dif, or dip-the' -re-ah) [di^Bspa, a skin or 

 membrane]. An acute, epidemic, infectious disease, 

 generally regarded as of specific contagious origin, 

 attacking especially the mucous membrane of the air- 

 passages, and producing profound depression of the 

 vital forces. It is characterized specifically by the 

 formation of layers of whitish or yellowish membrane 

 upon the mucous membrane of the pharynx, 

 nose, and larynx, and upon any existing cutaneous 

 abrasion. The duration of the disease is from one to 

 two weeks, death, when it follows, occurring usually 

 within a week. There are certain grave sequelae 

 that must be noted ; chief among these are various 

 forms of paralysis, especially of the palate. The 

 prognosis is always grave. To stain the microorgan- 

 isms of diphtheria see Loffler's Method, Grams 

 Method, — a fragment of false membrane being spread 

 on a cover-glass, dried, and otherwise treated as a 

 cover-glass preparation. D., Antitoxin Treatment 

 of, the treatment of diphtheria with subcutaneous in- 

 jections of the blood-serum of animals, and more es- 

 pecially the horse, rendered immune to diphtheria by 

 previous and repeated inoculation with progressively 

 increasing doses of the toxic products of the bacillus 

 diphtheria;. D. circumscripta, a peculiar form of 

 diphtheria described by Barrett, in which a distinct 

 circumscribed slough appears on one tonsil, and death 

 often results. D., Cutaneous, a form involving abra- 

 sions of the skin. D., Gangrenous, a gangrene of 

 the skin and mucous membrane sometimes accompany- 

 ing diphtheria. D., Laryngeal, a form involving the 

 larynx, threatening death by suffocation. D., Malig- 

 nant, a very fatal form, beginning with rigor, vomit- 

 ing, and attended with typhoid symptoms. D., Nasal, 

 a form in which the diphtheritic membrane spreads to 

 the nasal passages, and is accompanied by a fetid, 

 brown discharge. D., Secondary, a term designating 

 the occurrence of the disease in association with other 

 acute affections, such as typhoid fever, scarlatina, etc. 

 D., Paraffin Treatment of, the membrane is scraped 

 or peeled off, and paraffin is applied to the raw surface 

 every hour by means of a large camel' s-hair brush. 



Diphtheric (dif-ther'-ik) [diydepa, a skin or mem- 

 brane]. Pertaining to diphtheria. D. Conjuncti- 

 vitis, a form of conjunctivitis attended with an infil- 

 tration of coagulable matter or inflammatory products. 

 D. Membrane, the pellicle forming on the parts 

 involved in the diphtheric process. D. Paralysis, a 

 paralysis frequently affecting the muscles of the soft 

 palate and larynx, after the healing of the lesions of 

 these parts. 



Diphtheritic [difthcr-it'-ik) [di<ptiepa, a skin or mem- 

 brane], Same as Diphtheric, q.v. 



Diphtheritis (dif-ther-i'-tis). See Diphtheria. 



Diphtheroid (dif -iher-oid) [di<pt)epa, a skin or mem- 

 brane]. Resembling diphtheria. D. Throat. Syn- 

 onym of Herpetic '1 'on si /it 'is. 



Diphthongia (dif-thon' -je-ah) [die, double ; <pf>6 

 a voice]. The production of a double tone of the 

 voice by the incomplete unilateral paralysis of the re- 

 current nerve, or by some lesion of the vocal bands 

 that causes each portion of the glottis to produi 

 own sound. 



Diphycercal (dif-i-srr'-kal) [dupvqg, double ; * 

 tail]. In biology, applied to fishes that have the 



