CHLORAL 299 



action, paraplegia, dilated pupils and anaesthesia. These 

 symptoms may occur and be followed by recovery. The 

 anaesthesia is of spinal origin. Neither the sensory nerves, 

 motor nerves, nor muscles are affected except in the later 

 stages of poisoning. 



Insensibility to pain is said, by Brunton, to follow the 

 action of chloral upon the gray matter of the cord, by pre- 

 venting the transmission of painful sensations through this 

 tract. It is uncertain whether chloral acts as an hypnotic by 

 its direct depressing influence upon the brain tissue, or by 

 inducing cerebral anaemia in causing the bl'ood to be with- 

 drawn from the cerebrum into the dilated peripheral arte- 

 rioles. 



Respiration. — The respiration is not interfered with by 

 moderate nledicinal doses of chloral, but toxic quantities 

 depress and paralyze the respiratory centre. The respira- 

 tory movements become deep, regular and full, with large 

 therapeutic doses, but with toxic doses, slow, irregular and 

 shallow. Death occurs more commonly from arrest of res- 

 piration, yet primary heart failure, or both combined, may 

 lead to a fatal result. 



Temperature. — The temperature falls, owing to dimin- 

 ished heat production and increased loss, through heart 

 failure and vascular dilatation. 



Elimination. — Chloral is eliminated by the urine, in part 

 unchanged and in part in an altered condition. 



Summnry.—CYAoYsl is a local stimulant and antiseptic, 

 and relieves itching. It is a powerful depressant to the 

 cerebrum, vasomotor and respiratory centres, inferior cor- 

 nua, heart muscle and its ganglia. 



Acute Poisoning. — Large doses produce insensibility, 

 coma, and complete loss of muscular power, so that the 

 animal falls. There is general anaesthesia, and the pupils 

 dilate. The pulse is weak, at first frequent, later infrequent 

 and irregular. The respiration may be primarily quickened, 

 but subseqently becomes slow, shallow and irregular. The 

 animal sweats, the sphincters are relaxed, and involuntary 



