TOXIC EFFECTS 475 



such as occurs in man and occasionally in horses. Cats are 

 as much excited as horses or cattle, more so than dogs, 

 and hypnosis is produced with difficulty. 



Rabbits also have their motor and spinal centres promi- 

 nently affected, and convulsions are more common than 

 hypnotism. Mice receiving a fraction of a grain of morphine 

 are restless, have spasms, breathe irregularly, but sleep only 

 when dangerous doses are given. Birds are curiously 

 insusceptible ; relatively to their weight they take three 

 hundred times the dose given to man, do not sleep, or show 

 any alteration of the pupil. Pigeons swallowing ten grains, 

 or receiving hypodermically three grains, are seized with 

 inco-ordinate movements, laboured breathing, and convul- 

 sions ; the temperature falls sometimes five or six degrees, 

 and usually they die. Mixed with the food of poultry, 

 opium retards digestion, the crop remaining full for three 

 times the normal period. Cold-blooded animals are even 

 less susceptible than birds. In proportion to their weight, 

 frogs take with impunity a thousand times the dose that 

 would poison a man, and one or two grains cause convul- 

 sions, paralysis, and respiratory arrest. 



Toxic EFFECTS. Opium and its preparations annually 

 destroy in Great Britain upwards of one hundred human 

 lives, three-fourths being children under five years. In the 

 domesticated animals accidental poisoning with opiates 

 occurs occasionally, intentional poisoning very rarely. 



Horses without danger may be given by the mouth about 

 one hundred times as much opium as would poison a man. 

 Hertwig mentions that two to four drachms produce slight 

 stimulation, and that an ounce in solution caused first 

 increased liveliness, and, after two hours, dulness, diminished 

 sensibility, slower circulation, less frequent evacuations, and 

 stupor symptoms which continued for twelve hours, but 

 entirely disappeared the following day. Two ounces and a 

 half induced similar effects, with convulsions and death in 

 about twenty hours. Four drachms powdered opium caused 

 little effect for seven hours, and then only acceleration of 

 the pulse. Even four ounces of laudanum are stated to 

 have had little effect. 



Dun gave a strong, healthy cart-horse one ounce powdered 



