186 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



and in activity. One grain of sulphate of methyl-morphium, in solution, was 

 injected into the abdominal cavity of one of these frogs (a), and three-fourths of 

 a grain of morphia, dissolved in very dilute sulphuric acid, into the abdominal 

 cavity of the other (b). 



(a). Frog with Sulphate of Methyl-morphium. 



In eight minutes, the limbs yielded, and the frog 

 subsided on the abdomen and chest. 



In twenty minutes, it was perfectly flaccid, and 

 the respirations had entirely ceased. Pinching 

 of any portion of the skin excited energetic 

 movements of the leg whose vessels were tied, 

 and feeble movements in various other parts. 



In thirty minutes, the two sciatic nerves were 

 exposed ; galvanism applied to their trunks 

 caused contractions of the tied limb, below the 

 ligatures, and nowhere else. The heart was 

 now acting at the rate of forty-two in the 

 minute, and the idio-muscular irritability was 

 normal everywhere. 



In twenty-four hours, the frog was still perfectly 

 flaccid, the heart was contracting at the rate 

 of thirty per minute, and the muscles of the 

 poisoned and non-poisoned regions contracted 

 when directly galvanised. Galvanism of the 

 sciatic nerve of the poisoned leg, however, pro- 

 duced no movement; but galvanism of the 

 sciatic nerve of the non-poisoned leg, even 

 when applied to a part where the poison had 

 access, still caused vigorous movements below 

 the ligatures. 



(b). Frog with Sulphate of Morphia. 



In sixteen minutes, some slight sprawling occur- 

 red, before which the frog was jumping about 

 vigorously. 



In fifty minutes, pinching of the skin occasioned 

 a series of clonic spasms, in which both poste- 

 rior extremities were forcibly and slowly ex- 

 tended and then withdrawn, somewhat regu- 

 larly, during three or four minutes, about four 

 times in the minute. The movements then 

 ceased, but they could be again excited. 



In one hour, there was marked increase of the 

 reflex excitability, a slight touch causing a 

 spasmodic start. 



In one hour and thirty-eight minutes, a slight 

 touch of the skin excited a short tetanic con- 

 vulsion. 



In two hours, the same condition existed, and a 

 tetanic convulsion could be at any time excited 

 by a slight touch. During these convulsions, 

 the muscles in the non-poisoned limb were 

 contracted as forcibly as those in the poisoned 

 regions. 



In twenty-four hours, the frog was found dead, 

 with all its muscles rigid. 



These experiments prove distinctly tbat sulphate of methyl-morphium does 

 not possess, in any degree, the convulsant action of morphia, but that it causes 

 paralysis in place of convulsions. They also prove that this paralysis is due 

 to an effect on the motor nerves. We have further determined, by the same 

 method of experiment as has been already frequently described, that the 

 peripheral terminations are the parts of the motor nerves which are primarily 

 affected. 



Iodide of methyl-morphium produces the same effects on frogs as sulphate, 

 only a larger dose is required. 



The poisonous activity of sulphate of methyl-morphium does not appear to be 

 very different from that of a salt of morphia ; for we have seen that for rabbits 

 ten grains is about the minimum fatal dose of the former by subcutaneous 

 injection, and this contains about eight grains of morphia, which is little above 

 the fatal dose when subcutaneously exhibited. We have placed these and several 

 other results, in a form convenient for comparison, in the following table. 



