on lluscular Action tlirough the Nerve. 35 



My present iuvestigation was undertaken during the 

 months of September and October ; the weather at the time 

 being cold, and the frogs were getting apparently into a 

 torpid state, and certainly not so excitable as during the 

 summer months. It is well known that during the spring 

 months, at the time of spawning, the irritability of the 

 frogs is so great, that it is difficult to perform any experi- 

 ments upon them. The mere division of the spinal cord 

 will throw the animal into a state of tetanus ; and I have 

 even found that removing them from the water, and hand- 

 ling them, will be quite sufficient to produce the same state. 



Experiment III. — With Nitric Acid and Soda. 



With No. 1 solutions. — No contractions either in a or h. 



With No. 2 solutions. — Two contractions in a, one in b. 



With No. 3 acid and No. 2 soda. — Two powerful contractions 

 in a, and then slight fibrillar contractions ; three powerful con- 

 tractions in b. 



Experiment IV. — With Sulphuric Acid and Potash. 



With No. 1 solutions. — Slight contraction in a, none in 6. 



With N'o. 2 solutions. — One strong contraction in a, and then 

 slight fibrillar contractions; two strong contractions in 6, and 

 slight fibrillar contractions, but they did not last so long as those 

 in a. 



With No. 8 solutions. — Two strong contractions in b, three 

 strong contractions in a. 



Experiment V. — With Sulphuric Acid and Ammonia. 



With No. 1 solutions. — Slight fibrillar contractions in b, none 

 in a. 



With No. 2 solutions. — Two strong contractions in b, three 

 strong contractions in a, and slight fibrillar contractions. 



With No. 3 solutions. — Two strong contractions in a, three 

 strong contractions in 6, and then fibrillar contractions. 



Experiment VI. — With Sulphuric Acid and Soda. 



With No. 1 solutions. — A slight contraction in a, none in b. 



With No. 2 solutions. — Two strong contractions in a, and then 

 {flight fibrillar contractions ; one strong contraction in 6. 



With No, 3 acid and No. 2 soda. — I'wo strong contractions 

 in a, three strong contractions in b. 



