CHLORAL , 297 



smaller animals may be frequently moistened with a small 

 stick dipped in the solution, or it may be given in pill or 

 tablet. 



Class 4.— Chloral. 



Chloral. Chloral. C^H CI3O + H^O. . 



Synonym, — Chloral hydras, B. P.; hydrate of chloral, E.; 

 chloratum hydratum crystallisatum, P. G.; hydrate de chlo- 

 ral, Fr.; chloral by drat, G. 



A crystalline solid, composed of trichloraldehyde, or 

 chloral with one molecule of water. 



Derivation. — Dry chlorine gas is passed into absolute 

 alcohol until the latter is saturated. Aldehyde. and hydro- 

 chloric acid first result, C,H,0 H + 2 CI = C^H.O + 2 H CI. 

 The chlorine gas then acts upon the aldehyde, abstracting 3 

 atoms of hydrogen and replacing 3 atoms of chlorine, and so 

 forms chloral. C^H.O + 6 CI = C^H CI3O + 3 H CI. 



Chloral is purified first by distillation with sulphuric 

 acid, and then with lime, and when mixed with water forms 

 chloral hydrate (C^H CI3O + H^O). 



Properties. — Separate, rhomboidal, colorless, and trans- 

 parent crystals, having an aromatic, penetrating and slightly 

 acrid odor, and a bitterish, caustic taste. Slowly volatilized 

 when exposed to the air. Freely soluble in water, alcohol 

 or ether; also* in chloroform, benzol, benzin, carbon disul- 

 phide, fixed and volatile oils. It liquifies when triturated 

 with about an equal quantity of camphor, menthol, thymol 

 or carbolic acid. Chloral is decomposed by caustic alkalies, 

 alkaline earths and ammonia, chloroform being formed, and 

 a formate of the base produced. 



Dose.—R. k C, §i.-ii. (30.-60.); Sh. & Sw., 3i.-ii. (4.-8.); 

 D., gr.v.-xx. (.3-1.3). 



Action External. — Chloral is a strong irritant applied 

 locally in concentration to the skin and mucous membranes, 

 and if injected under the skin may cause abscess and 



