THE ACTIONS OF PHYSOSTIGMA AND ATROPIA. 575 



abnormal condition that was distinctly apparent consisted of frequently occur- 

 ring and well-marked fibrillary twitches. From this time the condition of the 

 animal steadily improved until perfect recovery took place. 



Experiment 57-b. — Nine clays afterwards, the rabbit which formed the sub- 

 ject of the previous part of this experiment received, by subcutaneous injection, 

 one grain of Dr Cook's extract of physostigma, suspended in 20 minims of 

 distilled water. Before the injection was made, it was ascertained that the 

 weight of the rabbit was three pounds and eight ounces and a half, and that the 

 pupils measured ^ths x i^}ths of an inch. 



Symptoms of poisoning very quickly appeared. In six minutes, the posterior 

 extremities were trailing, and the anterior considerably extended, and stumbling 

 movements occurred, while well-marked fibrillary twitches were present. In 

 eight minutes, saliva was escaping from the mouth in drops, and tremors 

 frequently occurred. In eleven minutes, the rabbit was lying on the abdomen 

 and chest ; several faecal pellets were passed ; the pupils were contracted 

 (-sVths x .^ths of an inch) ; and the respirations were rapid and accompanied with 

 mucous sounds. Soon afterwards, the head subsided until the lower jaw rested 

 on the table ; the arching of the back disappeared ; the pupils became still 

 further contracted (^yths x 5 3 oths of an inch) ; the cardiac contractions greatly 

 diminished in frequency and strength ; and the respiratory movements assumed 

 a gasping character. Feeble tremors then occurred, and the head was drawn 

 backwards ; after which a condition of general flaccidity set in. A few more 

 feeble gasps occurred, and then the respirations altogether ceased, at thirteen 

 minutes and thirty seconds after the commencement of the injection of 

 physostigma. 



In this experiment the power of atropia to counteract the lethal action of 

 the extract of physostigma prepared by Dr Cook is displayed in a very remark- 

 able manner. 



The second portion of the experiment shows that the lethal activity of this 

 extract is considerably greater than that of the extract prepared by myself. 

 Nevertheless, atropia so completely and successfully antagonised the lethal 

 action, as to prevent the occurrence of any symptom of serious import after the 

 administration of a dose twice as large as that by which death was afterwards 

 produced in about thirteen minutes. 



Summary of the preceding Experiments. — Before passing to the second por- 

 tion of this research, it may be of advantage to give a brief summary of the 

 various facts that have been brought forward. 



1. It has been shown by a statement of the result of several experiments, 

 that the minimum lethal dose for rabbits of extract of physostigma is 1 - 2 grain, 

 and that of sulphate of physostigmia 012 grain, for every three pounds weight 

 of animal. 



