1910.] Nicotine and other Pp-idine Bases upon Muscle. 335 



Sum mari/ of Recorded Ohscrvations. 



Nicotine Tarti-aU'. 



0"1 per cent, n/162 Typical etiect. 



0-1 „ m/162 



0-2 „ n/324 „ 



0-01 „ /1/1C20 „ Fig 1. 



then 0-1 „ «/lG2 No effect. 



0-01 „ Typical effect. 



then O'l „ No effect. 



0 01 „ Typical effect. 



then 0-] „ No effect. 



O'Ol „ Typical effect (originally small, then large. Fig. 2). 



then 01 „ No effect. 



0-01 „ Typical effect. 



then 0-1 No effect. 



0-01 „ Typical effect. 



0 001 „ No effect. 



then 0 01 „ Slight typical effect. 



Nicotine. 



0'081 „ ?i/200 Typical effect; abolition in 11 minutes; iinpeifect 



recovery after 20 minutes. 

 0'04] „ «/400 Typical effect ; abolition in 15 minutes ; fair recovery 



after 9 minutes. 



0'032 ,, n/500 Typical effect ; abolition in 17 minutes ; fair recovei'y 



after 5 minutes. 

 0-016 „ w/1000 Typical effect. Fig. 3. 



We find that the peculiar nicotine effect may fail to present itself at 

 lowered temperatures, and that it can be brought out into clearer evidence at 

 higher temperature. 



The characteristic nicotine effect cannot be produced twice in the same 

 muscle ; if, e.<j., it has been brought about by immersion of a nmscle in a 

 solution of O'Ol per cent, nicotine, it cannot be reproduced by a second 

 immersion in nicotine solution of ten times the strength (fig. 2), which simply 

 abolishes all muscular contractility. 



The characteristic effect fails to appear in the case of muscles removed 

 froui frogs that had received by subcutaneous injection a lethal dose of 

 curarine or of nicotine. 



The Pyridine Bases. — The study of nicotine naturally involves that of its 

 parent base pyridine, as well as that of methyl pyridine or picoline and of 

 piperidine or hexahydropyridine, the active principle of pepper. 



