II 



538 



HALF 



H 



H. Abbreviation of Hypermetropic!. In chemistry, the 

 symbol of hydrogen. In pharmacy, the symbol of 

 Haustus, a draught. 



Haarlem Blue. Same as Mineral Blue. 



Habena (hab-e' '-nati) [L. , "a rein"]. I. A peduncle 

 of the conarium. A slight ridge at the dorsal margin 

 of the mesal surface of the thalamus, with a dorsal 

 convexity, extending from the porta to the supracom- 

 missure, which unites it with its opposite. 2. A 

 bandage or strip of plaster for a wound. 



Habenal, or Habenar (hab-e'-nal, or hab-e' -nar) [ha- 

 bena, a rein]. Relating to the habena. 



Habenula (hab-en'-u-lah) [habena, a rein] . A ribbon- 

 like structure. The superficial gray nucleus of the 

 optic thalamus in front, and superior to the posterior 

 commissure. H. conarii. Same as Habena. H. 

 pectinata, perforativa, and tecta (or arcuata), 

 names of different zones, or portions of the basilar 

 membrane of the internal ear ; called also Zona pecti- 

 nata, etc. 



Habenular (hab-en'-ular) [habena, a rein]. Pertain- 

 ing to an habenula. 



Habit (hab'-it) [habere, to have]. I. That condition or 

 quality that one naturally possesses, or that may be ac- 

 quired. 2. The tendency to repeat an action or condi- 

 tion. 3. In biology, the general aspect of a plant or 

 animal and its mode of growth. H. -chorea. See 

 H. -spasm. H., Full, of a plethoric constitution. H.- 

 Spasm ; Habit-chorea ; Convulsive Tic ; Gilles de la 

 Tourette's Disease. A choreic disease characterized 

 by simply localized spasmodic movements, or such 

 movements combined with explosive utterances and 

 psychic symptoms (convulsive tic). Habit-spasm 

 is confined chiefly to young girls, and is marked mainly 

 by spasmodic action of the facial muscles or of the 

 head. Convulsive Tic or Gilles de la Tourette's Disease 

 is a psychosis allied to hysteria, and occurring usually in 

 children of a neurotic tendency. It is marked by 

 involuntary muscular movements, usually affecting the 

 facial or brachial muscles, and by explosive utterances 

 that may resemble a bark or an inarticulate cry. A 

 word heard may be mimicked at once and repeated 

 over and over again, usually with the involuntary 

 movements. To this the term Echolalia has been ap- 

 plied. Coprolalia, or the use of bad language, is 

 another symptom, and occasionally actions are mim- 

 icked (echokinesis). These may also be associated with 

 curious mental disturbances, the patient becoming the 

 subject of a form of obsession or a fixed idea. 



Habitat (hab'-it-at) [habitare, to dwell]. The natural 

 locality, or geographic range of an animal or plant. 



Habitation (hab-it-a' -shun) [habitation dwelling]. A 

 dwelling-place. The home, dwelling-place, or natural 

 locality of an animal or a plant. 



Habitus (hab'-it-us) [habere, to have]. A habit; gen- 

 eral appearance or expression. 



Habromania (hab-ro-ma' '-ne-ah) [a(Sp6c , graceful ; 

 fxavia, madness]. Insanity with pleasant or agreeable 

 delusions. 



Hachement (hahsh-mong)') [Fr., hacking, or chop- 

 ping]. In massage, a succession of strokes, usually 

 with the ulnar edge of the hand, sometimes with 

 the border of the percutor. 



Hackberry (hak'-ber-e). See Celtis. 



Hacking (hak'-ing). See Tapolement and Hache- 

 ment. 



Haddock {had' -ok) [ME., haddok, haddock]. A 

 fish, Gadus aglcfinus, closely allied to the cod. It 



is said that the oil of the liver of the haddock is some- 

 times mixed with cod-liver-oil ; but such admixture is 

 probably rare, as it greatly impairs the market 

 value of the oil. Unof. 



Haeckel's Law. See Law. 



Haema- {hem' -ah-) [alfia, blood]. A prefix signifying 

 some relationship with the blood. For words (unless 

 unanglicized) thus beginning, see Hema-. 



Haemal (hem'-al). See Hetnal. 



Haemanthin {hem-an' -thin) . See Hemanthin. 



Haematoxylin (hem-al-oks' -il-in). See Hematoxylon. 



Haemin (hem' -in). See Hemin. 



Haemo- (hem'-o-). For words thus beginning see 

 Hemo-. 



Haemorrhage (hem'-or-aj). See Hemorrhage. 



Haeser and Neubauer's Formula. A formula for 

 estimating from the specific gravity the total amount 

 of solids in the urine ; it is sufficiently accurate for 

 clinical purposes. The estimation is made by multiply- 

 ing the last two figures of the specific gravity by the 

 factor 2.33, the product of which represents the num- 

 ber of grams of solids in 1000 c.c. of the urine ; this 

 must be multiplied by the number of c.c. of the urine 

 under examination and divided by iooo in order to 

 obtain the correct amount of solids. 



Hagenia (haj-e' -ne-ah). See Kusso. 



Hager's Reagent. A reagent for the detection of 

 sugar in the urine. It consists of the ferrocyanid 

 of iron and caustic potassa. 



Hahnemannism (hahn'-e-man-izm). See Home- 

 opathy. 



Haidinger's Brushes. A visual phenomenon seen 

 upon directing the eye toward a source of polarized 

 light, due to the doubly-refractive character of the 

 elements of the macula. 



Hair (bar) [ME., here, hair]. The hirsute appendage 

 of the skin. Each hair consists of a bulb and a shaft. 

 The former is situated in the true skin, but is enveloped 

 in a sheath of epidermis. H. -blanching. See Can- 

 ities. H.-bulb, a whitish, soft, bulbous enlargement 

 at the proximal extremity of the root of the hair. H.- 

 cap Moss, Robin's Rye ; the leaves and stems of 

 Polvtrichum juniperum, a powerful diuretic. Dose of 

 the decoction ad lib. ; of the fld. ext. 5?j-ij. Unof. 

 H.-despoiler, an individual who is afflicted with a 

 form of sexual perversion, in which the feelings are 

 aroused during the act of mutilating or cutting-off the 

 hair of the victim. H. -follicle. See Follicle. H.- 

 gland, a minute sebaceous gland of the hair-root. 

 H.-knob, Henle's term for a hollow, bulbous hair- 

 root. H. -papilla, the nipple-like process of the 

 corium from which the hair grows. H. -pigment, 

 the coloring-matter of the hair. H.-pith, the medulla 

 of a hair. H.-root, that portion of a hair contained 

 in the follicle. H. -shaft, the part of a hair above the 

 root. (See illustration, page 539.) 



Hairy (har'-e) [ME., here, hair]. Covered with hairs 

 consisting of hair. H. Heart. See Trichocardia and 

 Cor villosum . H.Tongue. See Xigritics. 



Halberd-shaped (hal'-berd-shdf>l). Same as Hastate. 



Hale (hal) [ME., hcil, in good health]. Sound; 

 healthy ; robust. 



Half (ha(h)f) [ME., half, half]. Oneoftwoe<|u;il parts. 

 H.-bath. See Bath. H. -breed, a popular term 

 applied to offspring whose parents belong to differenl 

 races. H. -lying, in massage, reclining at an angle 

 of about 45 . H. Neck-rest, in massage, haying 

 one hand supporting the neck posteriorly. H.-wit, a 



