ATTENI \ I 1 1 >\ 



1 I!) 



A I RA 



Attenuation [at-ten-u-a* shun \\attenuare, to make thin], 

 A thinning, narrowing, or reduction of the strength 

 or size of a substance. A. of Microbes, weakening 

 pathogenic virulence of microbes bj su cul 



tares and other methods, so that the) may be used as a 

 vaccine to confer immunity from future attacks ol the 

 disease. A., Sanderson's Method of, by passing 

 the virus through the system oi anothei animal i 



the guinea pig, in anthrax |, so thai il bi i is modified 



in virulency. Toussaint and ( hauveau have shown 

 that heat is a valuable means of attenuation ; oxygen, 

 chemical reagents, exposure to sunlight, etc, , have also 

 been used. 



Atterminal [at-er'-min-al). See Adterminal. 



Attic {af-ik) [Allicus, Attic]. Part of the tym] 

 cavity situated above the atrium. A. Disease, chronic 

 suppurative inflammation oi the attic of the tympanum. 



Attitude i,/ - '-. -tud ) [aptitudo, aptitude]. See Posture. 

 A., Crucifixion, in hystero-epilepsy, a rigid state of 

 the body, the arm-- stretched out at right angles. A., 

 Frozen, a peculiar stiffness of the gait characteristic 

 of disease of the spinal cord, especially of amyotrophic 

 lateral sclerosis. A., Passionate, the assumption 

 of a dramatic or theatrical expression, a position 

 assumed by some hysterical patients. 



Attollens [at-oV-enz) [attollere , to rise up] . Applied to 

 muscles raising or elevating the part, as the A. Auris, 

 a muscle raising the external ear. See Muscles, 

 Table of. 



Attraction (at-rak'-shun) \attrakere, to draw to]. The 

 tendency of one particle of matter to approach another. 

 Affinity. As existing between celestial bodies it is 

 termed gravitation, while molecular attraction ox cohe- 

 sion expresses the force aggregating molecules into 

 masses. A., Chemical, the attraction of affinity, re- 

 lates to the attraction of atoms of one element to those 

 of others, resulting in chemical compounds. A., Cap- 

 illary, the tendency of a curved surface or a tube to 

 exert traction on a liquid. A., Electrical, the ten- 

 dency of bodies toward each other when charged 

 with opposite electricities. A., Magnetic, the influ- 

 ence of a magnet upon certain metallic substances, 

 chiefly iron. 



Attrahens [atf -rah-eni) [attrahens, drawing]. Applied 

 to muscles as Attrahens aurem, a muscle drawing 

 the ear forward and upward. See Muscles, Table of. 

 Also applied to medicines attracting fluids to a part, 

 as stimulants, epispastics, etc. 



Attrahent [at f -rah-ent) [attrahens, drawing]. i. 

 Drawing to; adducent. 2. A drawing application; 

 an epispasticor rubefacient. 



Attrition [at-risk' '-un) [atterere, to rub against]. An 

 abrasion or chafing of the skin. In physics, any rub- 

 bing or friction that breaks or wears the surface. 



Attypic (at-ipt-ik) [at, to; ri/irog, a type]. In biology, 

 possessing by acquisition or specialization the charac- 

 ters of a prototype. 



Atypic [ah-tip/-ik\ [d priv. ; ri-oc, a type]. Irregular; 

 not conformable to the type. A. Fever, an inter- 

 mittent lever with irregularity of the paroxysm. 



Atypical [ah-tip f -ik-al). See Atypic. 



Auante [aw-an f -te) [avavrq; avaivecv, todry]. A wast- 

 ing or atrophy. 



Auantic \aw-an' -tik) [avavriic6g, wasted]. Character- 

 ized by wasting ; atrophic. 



Aubernage [o-bar-nakzh') [Fr.l. A contagious disease 

 of the vine, called by the Italians the Black Disease. 

 It is doubtful whether it is due to a fungus or a bac- 

 terium. Cf. Bacterium gutnmis, comes, under Ba - 

 teria, Synonymatic Table of. 



Auburn System. See Ventilation. 



Auctioneers' Cramp. See Cramp. 



Audimeter [aw dim f ei er). Si e Audi 



Audiometer md-et-er) [audire, to heai 



a nn < un ] Aii instrument lor measuring tie- acute- 

 1 ing. 



Audiometric 1 nef-rik) [audire, to hear; 



10V, a measuri | Relating to audiometry. 



Audiometry [audire, to heai 



a measure]. I he measurement, or testing, of the 

 of hearing. 



Audiphone [aw' [audire, to he vi], a 



sound]. An instrument for improving thi power of 

 hearing by conveying sounds through the bones of 

 tin- head to the labyrinl h. 



Audition [aw-disk' '-un) [audire, to heai]. The act of 

 hearing. A. coloree, a peculiar association between 

 the auditory and optic nerves, by which a certain 

 sound or musical note will give- rise to a subjective 

 sensation ol color, the same note in the same person 

 being always assoi iated with the same color. 



Auditory [aw> '-dit-o-re) [audire, to hear]. Pertaining 

 to the act or the organs of hearing. A. After-Sensa- 

 tions, the sensation- oi sounds continuing or occurring 

 alter the cessation of the stimulus. A. Amnesia. 5i 

 Mind-deafness. A. Area, the cerebral center for hear- 

 ing ; its location is not definitely determined. A. 

 Aura, auditory sensation preceding an attack of epi- 

 lepsy. A. Center, same as A. .Ir,,/. A. Hairs, the 

 processes of the crista acustica, at present of indeter- 

 minate function. A. Meatus (external and internal 1, 

 the external and internal canals or openings of the ear. 

 A. Nerve, the portio mollis of the seventh pair of 

 cranial nerves. A. Ossicles, the chain of small bones 

 of the middle ear. A. Sac, the labyrinth, pit, or de- 

 pression in the epiblast on both sides of the embrvo- 

 logic after-brain. When cut off from the epiblast it 

 is called the vesicle of the labyrinth, or Primary 

 Auditory Vesicle. A. Teeth. See Teeth. A. 

 Vertigo, dizziness due to pathologic conditions 1 >f 

 the ear. See / 'ertigo and Meniere' s Disease. 



Auditus (a-io-tli'-fus) [1..]. Hearing; the sense or 

 power of hearing. 



Auerbach's Ganglia. See Ganglia, Table of. 



Auerbach's Plexus. See Plexuses. Tabic 



Augment [awg -ment) [augmentum, increase]. The 

 increasing stage of a fever or other acute disease. 



Augmentation [awg-men-ta f -shun) [augmentatio, an 

 increasing]. I. Same as Augment. 2. Increase in the 

 violence of symptoms. 



Augnathus [awg-na' -thus) [ai, besides; yvaBoc, the 

 jaw]. A monster with two lower jaw-. See />.- 

 sopus. 



Aula [aw'-lah) [av/Ji, a hall or open court]. 1. The 

 common mesal cavity of the cerebrum, it being also 

 the anterior portion of the third ventricle. 2. In 

 biology, a space or cavity formed by a colony 1 I 

 infusorians. 



Aulatela [aw-lat-e f lah) [aula, a hall; tela, a web]. 

 The roof or covering membrane of the aula. 



Aulic [aw'-lik) [ni'/i/, a hall]. I! :longing or pertaining 

 to the aula. A. Recess, a triangular depression 

 between the precommissure and the two fornicolumns 

 of the brain. 



Auliplexus [mv-le-pleks' us) [aula, hall ; plexus, a net- 

 work]. The choroid plexus of the aula. 



Aulix [aw f -liks)[aulix, a furrow]. The sulcus of Monro, 

 a groove on the mesal surface of the thalamus just 

 ventrad of the medicommissure. 



Aulophyte [aw / -/o-fit) \av7i6q, a pipeor tube; <f>v~6v, a 

 plant]. In biology, a symbiotic plant ; one that lives 

 within another, but not as a parasite. 



Aura [1 •'. a breath] A biv ind ; 



a -oft vapor. A sensation sometimes like a gentle 



