302 PROFESSOR C. R. MARSHALL ON 



one and a half minutes terminated by a few irregular clonic contractions and a longer 

 interval of rest (nine minutes). At 4.21, convulsions similar to those shown in fig. 5 

 commenced, and continued with great regularity for three and a quarter minutes. (A 

 second dose of tutin, 0*001 grm., was injected at 4.23^.) The convulsions then gradually 

 became longer owing to the development of an increasing terminal clonus until, at 4.28, 



4.22J 



Fig. 5. — Later contractions of right fore limb in decerebrate rabbit after tutin. Same animal, x j linear. 



they became similar to those shown at the beginning of fig. 6. They were now 

 continuous, a tonic stage with superposed slight clonic contractions of about three 

 seconds' duration alternating with a clonic stage lasting about fifteen seconds. As this 

 state seemed likely to continue, the effect of ether was tried, and it will be convenient 

 to describe it here. 



Influence of Anesthetics on the Convulsions. 



The effect of inhaling ether on the convulsions of the decerebrate animal is shown 

 in fig. 6. At the point marked by the arrow the animal was made to breathe ether 

 vapour of the strength used for inducing anaesthesia for operations, and this was 

 continued for eighty seconds. The convulsions ceased almost immediately after the 

 commencement of the inhalation, and very slight contractions recommenced two minutes 

 after its discontinuance. From this point the contractions, which at first were regular 

 in rhythm, increased in intensity, and finally assumed the alternating tonic-clonic 



