DICROTISM 



373 



DI I ll« I II \n INTESTINORI M 



Dicrotism [di' ' -kro-tizni) [diK/ioror, a double-beat]. 

 The quality of being dicrotic. A condition of the 

 pulse in which with every wave there is given to the 

 finger of the examiner the sensation of two beats. It 

 is present when the arterial tension is low. The second 

 shock is due to the recoil of the arterial walls when 

 the aortic valves are closed. 



Dictyitis [dik-te-i / -tis) [dinrvov, net, retina]. Retinitis. 



Dictyopsia (dik-te-op'-se-ali) [6'iktvov, net ; Hrpig, view]. 

 The sensation as if a net were stretched before the e\ ■ 



Dicyanogen (di-si-an'-o-jen) [die, double; cyanogen], 

 NC.CN. Free cyanogen ; a colorless, poisonous gas 

 of peculiar odor, and specific gravity 26 (11 = 1). It 

 may be condensed to a mobile liquid by cold of — 25 

 C. , or by a pressure of four atmospheres at ordinary 

 temperatures. In this condition it has a specific 

 gravity of .566, solidities at — 34° C. to a crystalline 

 mass and boils at — 21° C. It burns with a bluish- 

 purple mantled (lame. 



Didactic (di-dak 1 '-tik) [didanrtudg, apt at teaching]. 

 Teaching by description, rules, or principles ; opposed 

 to clinical. 



Didactylism {di-dak' -til-izm) [pig, double ; ddnrvlog, 

 a finger]. The condition of having congenitally but 

 two digits on a hand or foot. 



Diday's Operation. See Operations, Table of. 



Didot's Operation. See Operations, Table of. 



Diduction [di-duk'-shun) [diducere, to draw apart]. 

 Abduction of two parts ; the withdrawal of a part. 



Didymalgia [did-e-mal' -je-ah\ [d/dv/uog, testicle ; alo/og , 

 pain]. Pain in a testicle. 



Didymitis [did-e-mi / -tis\ [didv/nog, a testicle ; irn\ in- 

 flammation]. Orchitis affecting mainly the body of 

 the testicle. 



Didymium (di-diin' -e-nni) [didv/iog, twin]. A rare 

 metal of grayish or yellow color. See Elements, 

 Table of. 



Didymous (did'-int-us) [didvuor, twin]. Arranged in 

 a pair, or in pairs. 



Didymus (did' -im-ns) [didv/uog, twin]. A twin; a 

 twin-monstrosity ; a testis. 



Didynamous [di-din* -am-us\[6ig, two; diwa/ng, power]. 

 In biology, having the stamens in two pairs, one 

 longer than the other. 



Die (di) [ME., &»]. To cease to live; to become 

 dead. 



Diecious (di-e'-shus) [dig, two ; okor, house]. In bi- 

 ology, having the two sexes in different individuals, or 

 in two households, as staminate and pistillate flowers 

 separate and on separate plants. 



Dieffenbach's Operation. See Operations, Table of. 



Dielectric (di-e-lek'-trik) [did, through ; yAenrpov, 

 amber]. A non-conducting substance that transmits 

 electricity by induction. 



Dielectrics (di-e-lek' '-triks) [did, through ; jj?£KTpov, 

 amber]. The property of certain substances to per- 

 mit an inductive electric influence to act through or 

 across them. 



Dielectrolysis [di-e-lek-trol' '-is-is) [did, through; r/fen- 

 rpov, electricity ; Tweiv, to dissolve]. Galvanic elec- 

 trolysis of a compound, the current passing at the 

 same time through a diseased portion of the body and 

 carrying one of the elements of the compound with it. 



Dien {di'-eri) [did, through; ey/c£0ayoc, brain]. An 

 abbreviation of diencephalon. The name given to 

 the line of junction of the thalamus with the caudatum. 



Diencephal (di-en-sef-al' ). Same as Diencephalon. 



Diencephalon {di-en-sef '-al-on) [did, between ; i]netya- 

 Aag, brain]. That part <>f the brain between the 

 prosencephalon and the mesencephalon. It includes 

 the optic thalami and the third ventricle. 



Dieresis (di-er'-es-is) [d/aipraig, a division]. A solu- 



tion of continuity, as a wound, ulceration, etc. In 

 biology, the division of the outer branch of the pos- 

 terior or caudal pleopod of a crustacean. Bal 



Dieretic [di-er-ef '-ik) [dtaipkeiv, to divide"]. I'estruc- 

 tive; eschari itii ; c< irrosh e. 



Dies and Counter-dies. Metallic casts obtained by 

 molding in sand or dipping in molten zinc and lead, 

 or other alloys, such as babbitt metal, and which are 

 used for stamping up dental plates ; they are generally 

 described as male and female castings, between which 

 the plate is swaged. 



Diesel's Test. See Tests, Table of. 



Diet (di' -et) [diaira, a system or mode of living]. 1. 

 An arranged selection of food necessary to meet the 

 needs of the body. 2. To regulate the amount and 

 character of the food ingested. D. -drink, a medi- 

 cated drink, or beverage. D., Lisbon, a draught mui h 

 resembling the compound tincture of sarsaparilla. 

 D., Milk, one consisting mainly of milk. D., Tuff- 

 nell's, a highly nutritious diet including but a small 

 amount of liquids, employed in the treatment of 

 internal aneurysms. 



Dietarian (di-et-a' -re-ati) [diaira, a system or mode of 

 living]. A physician who pays special attention to 

 matters of diet. 



Dietary (ili'-et-a-re) [diaira, a system or mode of 

 living]. A system of food -regulation intended to meet 

 the requirements of the animal economy. 



Dietetic (cti-et-et'-ik) [diaira, a system or mode of 

 living]. Pertaining to diet. 



Dietetics (di-et-et'-iks) [diaira, a system or mode of 

 living]. The science of the systematic regulation of 

 the diet for hygienic or therapeutic purposes. 



Dietetist (di-et-et'-ist) [diaira, a system or mode of 

 living]. One who is expert in questions of diet ; a 

 dietarian. 



Diethylamin (di-eth-H' -am-in)[dig, double ; ethyl, amin~\, 

 NC 4 H n . A ptomaine, obtained from the pike-fish when 

 allowed to putrefy for six days in summer. It is an 

 inflammable liquid of strong basic properties, soluble 

 in water, and boiling at 57.5 C. It is non -poisonous. 



Dietic (di-e/'-ik) [diaira, a system or mode of living]. 

 Same as Dietetic. D. Diseases, those caused by 

 errors of diet. 



Difference-Theory (dif'-er-ens). A theory in explan- 

 ation of the galvanic phenomena of living tissues. 

 The theory is an expression of these facts : Protoplasm 

 when injured or excited in its continuity becomes 

 negative to the uninjured part ; when heated it becomes 

 positive ; and the surface-polarization diminishes with 

 excitement and in the process of dying. It is also 

 called Alteration-theory (Hermann'). 



Differential [difer-en'-shal) [differentia , difference]. 

 Pertaining to or creating a difference. D. Diagno- 

 sis. See Diagnosis. D. Rheotome. See Rkeo- 

 tome. D. Tone, a tone produced by two primary 

 tones when sounding simultaneously; the number of 

 the vibrations corresponds to the difference between 

 the two primary tones. D. Staining, a method of 

 staining tubercle-bacilli, syphilis-bacilli, etc., founded 

 upon the fact that if deeply-colored, and especially 

 with a mordant, they retain the color in the presence of 

 certain reagent- that decolorize the surrounding tis- 

 sues. Koch, Ehrlich and Weigert, Ziehl and Neel 

 son, Fiitterer, Gibbes, etc., have devised various 

 methods ot differential staining. 



Differentiation {dif-er-en-she-a' -shun) [differentia, dif- 

 ference]. Specialization of tissues, organs, or func- 

 tions. The gradual change of homogeneous material 

 into special tissues or organs. 



Difficultas intestinorurn (dif-ik-ul'-tas intes-tin-or'- 

 urn) [I-.]. Synonym of Dysentery. 



