ACTIONS AND USES 525 



5 per cent, solution, placed within the eyelids, produce 

 anaesthesia, constrict the vessels, lessen the power of accom- 

 modation, and dilate the pupil. This dilatation is more 

 notable in men and dogs than in horses and cattle (Frohner). 

 It is caused by stimulation of the sympathetic fibres supply- 

 ing the dilator muscle of the iris. When swallowed, cocaine 

 diminishes the sensations of hunger and thirst. Large or 

 repeated doses quicken circulation, increase blood-pressure, 

 breathing, and temperature, and heighten reflex irrita- 

 bility by their effect on the central nervous system, and 

 in the case of the heart, by depression of the vagal endings. 

 Still larger doses cause trembling and timidity, impair co- 

 ordination and equilibrium ; animals cannot walk straight, 

 have muscular trembling and rotatory convulsions, and die 

 from paralysis of respiration. It is excreted by the kidneys ; 

 but does not appear, however, to alter the proportion of 

 the urinary constituents. Applied to the mammary gland 

 it diminishes secretion of milk. 



Horses receiving 60 to 80 grains injected subcutaneously, 

 or about *005 gramme per kilogramme of body-weight, 

 according to Frohner, are restless, paw with the fore feet, 

 neigh, and exhibit timidity and excitement, the pulse rises 

 to 90-96, temperature is increased, salivation occurs, the 

 bowels are frequently moved, and the pupil dilated. After 

 fifty minutes the animal is in a state of frenzied excitement, 

 with greatly augmented reflex activity. Two hours elapse 

 before these effects disappear. In COWS like effects were 

 produced by hypodermic injection of similar doses. One 

 drachm is stated to have produced excitement bordering on 

 madness, and continuing for four hours, but gradually pass- 

 ing off, and leaving no injurious effects. 



In dogs, doses consisting of "015 to '02 gramme per 

 kilogramme of live-weight produce psychical excitement, 

 muscular spasms, rhythmical contractions of the skeletal 

 muscles, circus-movements, wild galloping, tetanic and 

 clonic spasms, epileptiform fits, dyspnoea, rolling, and loss of 

 co-ordination. The spasms and more prominent symptoms 

 do not, however, occur when potassium bromide, ether, 

 or amyl-nitrite has previously been given. Large doses 

 subsequently paralyse the central nervous system in the 



