I9I3] Alfred P. Lothrop 459 



found that tubercular areas in the lungs contained from two to 

 three times as much calcium as normal lung tissue. The work is 

 in progress, 



71. On the localization of the convulsive action o£ potassium 

 sulfocyanate.^^ Charles C. Lieb. Potassium sulphocyanate, in- 

 jected into the anterior lymph sacs of frogs (Rana pipiens) in doses 

 of 0.125 to 1.5 mg. per gram of frog, induces convulsions of the 

 strychnine type. Larger amounts cause progressive depression and 

 death without any apparent Stimulation. The smaller doses cause 

 first some depression so that the animal corresponds to the de- 

 cerebrate frog. A little later the croak reflex is lost, and soon the 

 frog is unable to right itself when placed on its back. The spinal 

 reflexes are then depressed or may even be abolished ; a few minutes 

 later there is a return of these reflexes. which become more and 

 more active until finally typical tetanic convulsions appear. These 

 are usually of very short duration (two to ten seconds) and are 

 succeeded by a period of relaxation, during which Stimulation of 

 skin, tendons, and joints is almost without effect. Then irritability 

 returns and convulsions again appear. This cycle can be elicited 

 repeatedly but eventually recovery from the exhaustion becomes less 

 and less complete and finally all reflexes are lost. Pithing such 

 an animal, or pricking its exposed cord, is usually without effect ; 

 i. e., the cord is paralyzed. Direct electrical or mechanical Stimula- 

 tion of nerves and muscle shows that they are still active. 



The convulsions are not due to any effect on the muscle or its 

 nerve endings. If the sciatic nerve of a pithed frog be isolated 

 and the rest of the leg ligated, and then potassium sulfocyanate 

 injected below the ligature, no local or general convulsions develop. 

 If at the end of an hour and a half the ligature be cut, typical 

 tetanus appears within forty-five minutes. If one sciatic nerve of 

 a pithed frog be isolated and the rest of the leg ligated en masse, 

 and potassium sulfocyanate injected into the anterior lymph sac, 

 then both legs participate in the convulsions. If, after the increased 

 reflexes or convulsions appear, the sciatic be divided low in the 



" Conducted in the Pharmacological Laboratory of Columbia University as 

 one of a series of researches in collaboration with Drs. Gies and Kahn in this 

 Laboratory under the auspices of the Dental Society of the State of New York. 

 See BiocHEMiCAL Bulletin, 1912, ii, p. 178. 



