486 DR T. R. ERASER ON SOME UNDESCRIBED TETANIC SYMPTOMS 



about the 4 5^xoi>th °f tne weight of the frog, was sufficient to produce in it violent 

 tetanic symptoms, which lasted for many hours, and terminated in recovery. 

 When such a dose is given to a male frog, or to a female whose abdomen is not 

 greatly enlarged by distended oviducts, it is of interest to note that the anterior 

 extremities become incurved at the commencement of the tetanic symptoms, and 

 continue so until these disappear ; thus imitating a symptom produced by atropia 

 that has been fully describedin this paper (Section A.) 



It was also found that doses of sulphate of methyl-strychnium, varying from 

 the Woo tn to the i5ooo tn °f the weight of the frog, were sufficient to produce 

 complete and prolonged paralysis of the motor nerves, without causing death. 



Guided by these results, I then administered to frogs combined doses of 

 strychnia and sulphate of methyl-strychnium. After making several experi- 

 ments, I at length discovered that the remarkable combination of paralytic and 

 tetanic symptoms that has been described in Section A. of this paper could be 

 exactly imitated by administering to frogs a mixture of strychnia with sulphate 

 of methyl-strychnium in a certain proportion. 



The following experiment is sufficient to confirm this statement : — 



Experiment LXI. — One minim of a mixture of two minims of liquor strychnia? 

 (B.P.) in eighteen minims of distilled water (equivalent to Toftyoirths of a grain of 

 strychnia), was added to three minims of a solution of one-tenth of a grain of 

 sulphate of methyl-strychnium, in ten minims of distilled water (equivalent to 

 three-hundredths of a grain of sulphate of methyl-strychnium), and the four 

 minims of solution thus obtained was injected under the skin at the right flank 

 of a male frog, weighing 355 grains. In two minutes, some sprawling was 

 observed ; in three minutes, the frog was unable to jump, and the respiratory 

 movements of the chest had ceased ; in twelve minutes, only extremely feeble 

 and sluggish reflex movements could be excited by pinching the skin ; in fourteen 

 minutes, the lower jaw rested on the table, the respiratory movements of 

 the throat ceased, and the frog was perfectly flaccid ; and in thirty-five 

 minutes, it was impossible to cause any reflex movement whatever even by 

 severe excitation of the skin. During all this time, there was not the faintest 

 strychnic symptom. The reflex activity was frequently tested. At the com- 

 mencement of the experiment, it was perfectly normal ; and as the symptoms 

 advanced, the only change observed was a gradually increasing feebleness. At 

 forty minutes, it was found, by exposing a sciatic nerve, and subjecting it to 

 galvanic stimulation, that motor-nerve conductivity was completely suspended. 

 At this time, the cardiac impulse was good, and the heart's contractions occurred 

 twenty-eight times in the minute. 



On the second day — twenty hours after the administration — the frog was 

 lying on the abdomen with the thorax raised and supported by the anterior ex- 

 tremities, which were rigidly incurved, and there were infrequent respiratory 



