140 niOTOGRAPHS. 



Infu'sion. — Liquor the virtues of wliich have been obtained 

 by .steeping, without boiling. 



Lin'iment. — An unctuous medicine, containing usually oil or 

 lard, which is used externally in the form of friction. 



Liq'uor. — A name given to many compound licjuids, and espe- 

 cially to those the bases of which are water and alcohol. 



Lo'tion. — A liquid intended for application to any external part 

 of the body. 



Mix'ture. — A liquid medicine which contains not only extracts, 

 salts, and other substances soluble in water, but powders, 

 etc., which are insoluble. 



Pill. — A simple or compound medicine, weighing from one to 

 five grains, of a firm consistence and spherical form ; in- 

 tended to be swallowed at once without chewing. 



Tinc'ture. — Spirituous solutions of vegetable, animal, and some 

 saline substances. 



TJn'guent. — A soft composition used as a topical remedy for 

 sores. 



PHOTOGRAPHS. 



Photog'raphy (Gr. ^)7«(7s, light, and groplio^ I write). — The 

 art or practice of producing facsimiles or representations 

 of objects by the action of light upon a prepared surface. 

 The pictures, however obtained, are called iicc/atlve plmto- 

 ffvfrphs, and those which have their lights and shadows 

 disposed as in nature — dark upon a light ground — are 

 ])ositive plioiographs. 



Am'bl'otype. — A picture taken on a plate of prepared glass, in 

 which the lights are represented in silver and the shades 

 are produced by a dark background, visible through the 

 unsilvered portions of the glass. 



Cal'otype (Gr. kalos, beautiful, and tiqios, a sketch). — A pro- 

 cess for obtaining photogenic drawings on paper by the 

 action of light upon certain salts of silver. 



Cam'era-Obscu'ra (Lat., a dark chamber). — An apparatus 

 representing an artificial eye, in which the images of ex- 

 ternal objects, received through a double convex glass, are 

 exhibited distinctly and in their native colors, on a white 

 surface placed on the focus of the glass within a darkened 

 cliaraber. 



Chro'matype (Gr. cJu-oma, color, and tiqjos, a sketch). — A 



