CEREBRAL DEPRESSANTS. 133 



lar relaxation, and a very great fall in temperature. 

 Toxic doses cause death from paralysis of the car- 

 diac motor ganglia and the respiratory centre, or by 

 sudden heart failure in fatty degeneration, the heart 

 being arrested in diastole with the right cavities dis- 

 tended; hence it must be very carefully used on 

 patients affected with heart trouble of any kind or 

 advanced pulmonary disease. 



Chloral is not a true anodyne, as it neither inter- 

 rupts the transmission of pain nor does it affect the 

 conductivity of the sensory nerves, but overwhelms 

 the brain centres, thus rendering the animal uncon- 

 scious of pain; and hence it may be called an in- 

 direct anaesthetic. Chloral is rapidly diffused in the 

 blood, being supposed to set free chloroform due to its 

 decomposition by the blood, which is an alkaline fluid. 

 It increases the fluidity of that tissue, crenates the red 

 corpuscles, in large quantity destroys the leucocytes, 

 prevents the coagulation of fibrin, and produces a gen- 

 eral anaemic condition. It is excreted, partly un- 

 changed, by the kidneys, causing some diuresis, and 

 also by the skin. 



Treatment of Chloral Poisoning. — Atropine in 

 small frequently repeated doses is the best antagonist, 

 as it counteracts the depression of the chloral on the 

 heart, respiration, and cerebro-spinal sj'stem. Mor- 

 phine is sometimes given with chloral to prevent the 

 tendency to cardiac failure. 



Therapeutics. — Chloral is given to quiet irrita- 

 bility and to cause sleep, to relieve gastro-intestinal 

 irritation and spasm — as in colic. But as it is a topi- 



