910 



SCIENCE. 



[N. S. Vol. V. No. 12R 



lifting a weight and in extending a spring 

 were simultaneously recorded. It was evi- 

 dent that the ergograph curves did not give 

 a correct measure of fatigue, and of course 

 gave no record when the weight was not 

 lifted, whereas the ergometer curves meas- 

 ured more nearly the actual course of 

 fatigue. The instrument is being used in 

 the psychological laboratory of Columbia 

 University to study fatigue and the effects 

 of sensations and emotions on movements. 

 The Form of the Muscle Curve. F. S. Lee. 



Under the author's direction the curve of 

 contraction has been studied with improved 

 apparatus in the muscles of the turtle, by 

 Messrs. Furman and Turnure, and in the 

 muscles of the frog, by Messrs. Beer and 

 Gould. In the turtle the curves of dif- 

 ferent muscles differ greatly in form and 

 time relations. The period of shortening 

 is from two to five times that of the frog's 

 gastrocnemius. A feature of interest is the 

 enormous length of the period of lengthening 

 which, e. g., in the pectoralis major, may 

 amount to fifteen seconds or three hundred 

 times the period of the frog's gastrocnemius. 

 "With the present tendency to consider 

 muscular relaxation an active rather than 

 a passive phenomenon, this whole period of 

 lengthening must be taken account of in 

 determining the time relations of the mus- 

 cular contraction. The turtle's muscles 

 respond more readily to the make of an in- 

 duction current than to the break, thus dif- 

 fering from those of the frog, and evidently 

 possessing less irritability than the latter. 

 This fact, as well as that of the very long 

 curve of contraction, is in harmony with 

 the sluggish movements of the animal. 



In the frog the curves of different mus- 

 cles thus far studied resemble one another 

 in form and time relations much more 

 closely. Some muscles seem to show a 

 physiological resemblance to those of the 

 turtle in having a prolonged period of re- 

 laxation. 



The Nerve Impulse in its Relations to the- 

 Strength of the External Stimulus. C. W. 

 Gkeene. 



The electric current which occurs in an 

 isolated living nerve when a nerve impulse 

 passes along its course may now be consid- 

 ered as a qualitative and quantitative meas- 

 ure of nerve physiology. The auther has 

 reinvestigated and extended "Waller's re- 

 sults on this action current. Isolated 

 nerves of frogs, turtles, cats and dogs, five 

 to six centimeters long, were placed across 

 stimulating and leading-off non-polarizable 

 electrodes in a moist chamber. The faradic 

 stimulating current was measured by an 

 electro-dynamometer and the action cur- 

 rent by a delicate Rowland galvanometer. 

 (1) With equal increments of increase in 

 stimulus above that necessary to produce a 

 minimal deflection to a strength necessary 

 to produce a maximal muscle effect there is 

 a very rapid increase of action current and 

 by equal increments. (2) With further 

 increase in stimulus there is in the action 

 current a continued strong increase, at first 

 by equal but later by diminishing incre- 

 ments. If the results be plotted, the 

 stimuli being placed along the abscissa and 

 the successive action currents erected as 

 ordinates, the curve here shows a concavity 

 toward the abscissa. (3) With still stronger 

 stimuli, to tenfold and more, there is only 

 a slight further increase in action current 

 and by equal proportional increments. This 

 limb of the curve is important in its bear- 

 ing on the nature of the nerve impulse. 

 Some Observations in a Case of Human Pancre- 

 atic Fistula. F. Pfaff. 

 The subject of the observation was a 

 male patient in the City Hospital of Bos- 

 ton. Dr. H. W. Cushing had operated on 

 the patient for an abdominal tumor. As a 

 result of the operation a fistula formed, 

 through which a clear watery fluid was 

 secreted. This fluid had an alkaline re- 

 action, digested proteids with formation of 



