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Drs. T. L. Brunton and J. T. Cash. [June 21, 



compounds have a greater tendency to exaggerate the irritability of 

 the muscle at first. 



Salts of methyl, ethyl, and amyl ammonium are more active than 

 the corresponding ones of the di- and tri-compounds, but the tetra- 

 compounds are most active of all. 



In the next part of the paper the effect of salts of the alkalies 

 on muscle and nerve are considered. The substances investigated 

 were the chlorides of lithium, sodium, potassium, rubidium, and 

 caesium. These differ from ammonia in having very little tendency 

 to stimulate the spinal cord, and the chief symptom of poisoning by 

 them is increasing torpor. 



Slight excitement of reflex action is noted at first in the case of 

 potassium and rubidium. 



The motor nerves are not paralysed by caesium or rubidium except 

 in very large doses, but the other substances of this group paralyse 

 them to a greater or less extent. Lithium and potassium are the 

 most powerful. 



The contractile power of muscle (as shown by the height of curve) 

 is increased by rubidium, ammonium, potassium, and caesium. It is 

 unaffected by sodium excepting in large doses, and is almost invariably 

 diminished by lithium. 



The duration of contraction, as shown by the length of the curve, 

 is increased by rubidium and ammonium in large doses, by sodium, 

 and caesium. It is shortened by ammonium, lithium, and rubidium in 

 small doses, and by potassium. The contracture or viscosity is in- 

 creased by rubidium and ammonium in large doses, by lithium, and 

 sodium. It is diminished by rubidium and ammonium in small doses, 

 by caesium, and potassium. 



The action of substances belonging to the alkaline earths and 

 earths, is discussed in the next section. The substances investigated 

 were the chlorides of calcium, strontium, barium, beryllium, didymium, 

 erbium, and lanthanum. In regard to their action upon the nervous 

 system, these substances fall into two groups, (a) containing beryllium, 

 calcium, strontium, and barium; and (b) containing yttrium, didymium, 

 erbium, and lanthanum. Group a has a tendency to increase reflex 

 action as evidenced by spasm or tremor. With group b reflex action 

 in the cord appears to be little affected, but they appear to have a 

 tendency to paralyse motor centres of the brain in the frog. 



Group a all paralyse motor nerves to some extent. Lanthanum has 

 also a slight paralysing action, but the other members of group b have 

 not, agreeing in this respect with sodium and rubidium, and differing 

 from all the others. 



In regard to their action on muscles these substances cannot be 

 divided into sub-groups. The contractile power of muscle is increased 

 by barium, erbium, and lanthanum. It is sometimes increased and 



