RAY'S MANIA 



1240 



REAGENT 



in cyme of wild hydrangea. Rs., Actinic, solar rays 

 that produce chemic change. Rs., Bipolar, rays 

 leading from one point of divergence to another, as 

 in the diaster of a cell undergoing indirect division. 

 Rs., Chemic. See Rs., Actinic. R., Extraordin- 

 ary, the polarized ray that departs farthest from the 

 ordinary law of refraction. Its vibrations are parallel 

 to the vertical axis. R., Fin-, one of the radiating, 

 bony spines forming the framework of the fins in 

 fishes. R. -floret. Same as R. -flower. R. -flower, 

 one of the marginal flowers of an inflorescence when 

 distinct from those of the disc. R. -fungus. See 

 Actinomyces. R., Medullary, one of the vertical 

 partitions of parenchyma radiating from the pith to the 

 bark in woody plants, and separating the bundles of 

 fibro-vascular tissue. R.-oil, the oil of the liver of 

 the fish called ray or skate, Raja batis, said to be an 

 effective substitute for cod-liver oil. R., Ordinary, 

 the polarized ray which follows most nearly the ordi- 

 nary law of refraction. Its vibrations are perpendic- 

 ular to the vertical axis. 

 Ray's Mania. A form of general moral insanity. See 



Diseases, Table of. 

 Raygat's Test. See Birth. 

 Raymond's Blue. Same as Napoleon Blue. 

 Raynaud's Disease. A vascular disorder character- 

 ized by three grades of intensity: (a) Local syncope, 

 observed most frequently in the extremities, and pro- 

 ducing the condition known as dead fingers or dead 

 toes ; it is analogous to that induced by intense cold, (b) 

 Local asphyxia, which usually follows local syncope, 

 but may develop independently. Chilblains are the 

 mildest manifestation of this condition. The fingers 

 and toes and the ears are the parts usually affected. 

 In the most extreme degree the parts are swollen, 

 stiff, and livid, and the capillary circulation is almost 

 stagnant, (c) Locator symmetric gangrene, the mildest 

 form of which follows local asphyxia. Small areas 

 of necrosis appear on the pads of the fingers and of the 

 toes, also at the edges of the ears and tip of the nose. 

 Occasionally symmetric patches appear on the limbs 

 or trunk, and in severe cases terminate in extensive 

 gangrene. Raynaud suggested that the local syncope 

 was produced by contraction of the vessels ; the as- 

 phyxia is probably caused by dilatation of the capil- 

 laries and venules with persistence of the spasm of the 

 arterioles. Two forms of congestion occur, which may 

 be seen in adjacent fingers, one of which may be 

 swollen, intensely red, and extremely hot; the other 

 swollen, cyanotic, and icy cold (Osier). See Spha- 

 celoderma. R.'s Gangrene. Same as R.'s Disease. 

 R.'s Phenomenon. See Acroasphyxia and Dis- 

 eases, Eponymic, Table of. 

 Re-. A Latin prefix signifying back or again. 

 Reabsorption \re-ab-sorp'-shun). See Resorption. 

 Reaching (rech'-ing) [ME., reckon, to reach]. To 



attempt to vomit ; to retch. 

 Reacquired (re-ak-wird f ) [re, again ; acquirere, to ac- 

 quire]. Acquired a second time. R. Movements. 

 See Acquired Movements. 

 Reaction {re-ak'-shun) [re, again; agere, to act]. I. 

 Mutual action ; interaction. The response of an organ, 

 tissue, or the system, to a stimulus, agent, or influence. 

 Recuperation or return of power after depression or 

 " shock." The supervention of fever after a surgical 

 operation, or trauma. 2. In chemistry, the result of 

 introducing a reagent or tests See Tests, Table of. 

 3. In electro therapeutics, the muscular contraction 

 following the making or breaking of the current. R., 

 Acid, the reddening of blue litmus paper by the action 

 of an acid; a test for the presence of acids. R., 

 Adamkiewicz's, a reaction employed as a test for 



albuminoids. See Tests, Table of. R., Alkaline, a 

 reaction indicative of alkaline properties, and in 

 which red litmus paper is changed to blue. R., Am- 

 phicroitic, R., Amphigenous, R., Amphoteric, a 

 double reaction occurring occasionally in urine, owing 

 to the presence of substances by which the liquid re 

 sponds to both the acid and alkaline tests. R., Biuret. 

 See Tests, Table of. R. of Degeneration ("/A .A'." 

 diminution and loss of faradic excitability in both m 

 and muscles, the galvanic excitability of the muscles 

 remaining unimpaired, sometimes notably increased, 

 andalwaysundergoing definite qualitative modific; I 

 It is due to a degenerative atrophy in the nerves and 

 muscles, eventually in the muscles only, whose origin is 

 always nervous, paralytic, or atrophic, and whose s 

 in the peripheral nerves, motor roots, or central grav 

 substance. Strict cerebral disease is excluded. The 

 lesion is either in the peripheral nerves or spinal cord. 

 De. R. is of special value in prognosis. "When there 

 is only Partial De. R. (/. <?., slight diminution oi 

 galvanic and faradic excitability, " a less maximum 

 contraction rather than a laterminimum "),the di 

 will probably last one or two months ; if complete, it 

 will last much longer. The De. R. embraces the fol- 

 lowing modifications of irritability : 1 . Disappearance 

 or diminution of nervous irritability to both galvanic 

 and faradic currents. 2. Disappearance of faradic 

 and increase of galvanic irritability of muscles, gener- 

 ally associated with an increase of mechanical irrita- 

 bility. 3. Disappearance of faradic and increase of 

 galvanic muscular irritability, associated generally with 

 increased mechanical irritability. 4. Tardy, delayed 

 contraction of muscles, instead of the quick reaction 

 of normal muscles. 5. Marked modification of 

 normal sequence of contraction. A special variety of 

 the De. R. is the so-called Reaction of Exhaustion, 

 which is a condition of nervous and muscular irrita- 

 bility to electric excitation in which a certain reaction 

 produced by a given current-strength cannot be repro- 

 duced without an increase of current-strength. R, 

 Galvano-trophic, of L. Herrmann, a phenomeno 

 observed in small aquatic animals subjected to the in- 

 fluence of a galvanic current. After a few spasmodic 

 movements, they place themselves in the direction of 

 the current, with the head toward the positive 

 R., Gmelin's. See Tests, Table of. R., Hemiopic 

 Pupillary, of Wernicke, a reaction in which 

 of light thrown on the blind side of the retina 

 rise to no movement in the iris, but thrown upon tin 

 normal side produces contraction of both hides. R- 

 impulse, the supposed recoil of the cardiac ventricle 

 after the discharge of the blood into the, aorta ai 

 pulmonary artery. R., Isofaradic, of Adamkii 

 a condition of muscle in which it responds 01 

 faradic current. R., Myotonic, of Erb, 

 seen in Thomsen's disease, in which there is quant 

 tative and qualitative increase in the farad 

 bility. R., Neutral, a reaction indicating th 

 of both acid and alkaline properties ; 

 opposite qualities. R. -period, the period followfalj 

 trauma or operation in which there is recovery fr 

 the' incident shock. R.-time, in physii 

 psycho-physics, the interval between the applictB 

 of a stimulus and the beginning of the con 

 muscular contraction. R., Xanthoproteic. 

 Table of 

 Readjustment {re-ad- just' -menf). See./ 

 Reagent [re-a'-jent) [re, again ; ager, . to act]. 

 chemistry, anything used to produce a reaction, <»r 

 test for the presence of an element. A test, • 

 Tests, Table tf R., General, a reagent that indie* 

 the group of substances to which abody belongs, «:'.r. 



