298 INORGANIC AGENTS 



sloughing. It is a powerful antiseptic, and relieves itching^ 

 especially in combination with camphor. 



Action Internal. — Alimentary Canal — Chloral produces 

 severe irritation of the mucous membrane in concentrated 

 solution (20 per cent, or over), and large doses may cause 

 vomiting in dogs. The writer has seen intense glossitis and 

 stomatitis follow the breaking of a gelatine capsule, contain- 

 ing chloral, in the mouth of a horse. 



Blood. — Chloral is absorbed into the blood unchanged. 

 It was formerly thought that the action of chloral was due 

 to chloroform produced by the decomposition of the former 

 in the alkaline blood. C,H CI3O + KH0 = CHC1, + 

 K C H O3 (formic acid). 



It is now known that the blood is not sufficiently alka- 

 line to decompose chloral, and that chloroform is not found 

 in the blood, tissues or excretions, except in the case of the 

 urine, when it is strongly alkaline. Moreover, chloral acts 

 as usual upon a frog when the blood of the batrachian is 

 replaced by a neutral saline solution. 



Hea7't and Blood Vessels. — Chloral in large doses depres- 

 ses the action of the heart muscle, its contained ganglia, and 

 the vasomotor centres. It also produces local paralysis of 

 the vascular walls. Blood pressure is therefore lowered. 

 In small medicinal doses the circulation is not influenced 

 materially, but in poisoning the pulse becomes slow, weak 

 and irregular, and the heart is arrested in diastole. 



Nervous System — The salient action of chloral is exerted 

 upon the brain and cord. Like other narcotics, the depress- 

 ing effect may be preceded by a transient and unimportant 

 excitation of the brain and cord ; but this commonly passes 

 unnoticed, and the prominent action of chloral consists, in 

 ordinary doses, in depressing the higher functions of the 

 brain, and in larger doses, the motor tract of the cord. 

 Moderate therapeutic doses cause, therefore, dulness and 

 sleepiness (with contracted pupils) in the lower animals, 

 while doses approaching the toxic limit produce insensibi- 

 lity, coma, paralysis of the inferior cornua, with loss of reflex 



