On the Latent Period of Muscle Contraction. 467 



lafced directly, and under varying burdens but constant room 

 temperature, is strictly parallel. Upon the influence which curare 

 may exercise upon the curve of contraction, we cannot enter here. 

 The weight was gradually increased from lever to 100 grms. 



Table IT. — Contrast between Cararised and Non-Curarised Muscle. 



No. 



Weight. 



Length of latency 

 in tW- 



Length of curve 



Altitude in 

 millhns. 



Non-cur. 



Cur. 



!N"on-cur. 



Cur. 



Non-cur. 



Cur. 



1 and la 



Lever 



1 -85 



1-85 



30-0 



29-5 



31 5 



29-0 



2 „ 2a 



10 grms. 



1-9 



1 -9 



24-5 



26 -0 



20-0 



17-5 



3 „ 3a 



20 „ 



2-02 



2-0 



23 -0 



20-5 



17-5 



15 -0 



4 „ 4a 



30 „ 



2-10 



2-05 



22-5 



20 -0 



16-5 



13 5 



5 „ 5a 



40 „ 



2-30 



2 25 



21-75 



19 -75 



16-0 



11 -5 



6 6a 



50 „ 



2-47 



2 5 



21 -25 



19-6 



15-0 



11 -o 



7 „ 7a 



60 „ 



2-5 



2-6 



21 -20 



19 -75 



13 5 



11 -o 



8 „ 8a 



70 „ 



2 -65 



2-72 



21 -25 



20 -0 



13 -0 



10 5 



9 „ 9a 



80 „ 



2-80 



2 -85 



22 -35 



20-5 



13-5 



10-0 



10 „ 10a 



90 „ 



2-90 



2-95 



22-5 



21 -5 



12 25 



95 



11 „ 11a 



100 „ 



3-00 



3-00 



22 -75 



22-0 



12 -0 



9-0 



There are slight variations usually in the second place of decimals 

 between the two columns, but if the figures are — as we believe them 

 to be-— true measurements, we still require more extensive proof of a 

 permanent difference than the occasional variation of a ^oVo " • 



Our result then is that at room temperature, the latency of the 

 curarised and non-curarised muscles directly stimulated is equal for 

 equal weights. 



3. What is the relationship as to latency of the free-weighted muscle 

 tensed in proportion to the weight it carries, to the after- weighted 

 muscle, which has only the same slight initial tension under similar 

 weights ? As this question seemed to us to be an interesting one, we 

 made a few observations, so as to obtain a fair contrast between two 

 muscles placed under these widely differing circumstances. 



The after-weighted muscle was supported, so that the weight of 

 10 grms. just rested upon the catch, from which the contracting muscle 

 raised it. We give a double column of the resulting differences of the 

 free-weighted and the after- weighted muscles. 



The influence of the support seems to increase the earlier latencies, 

 and it is in great measure owing- to this effect that the variation is so 

 much greater in the case of the after-weighted than of the free- 

 weighted muscle. 



