398 



SIR THOMAS R. FRASER AND MR ALTSTER T. MACKENZIE ON 



Experiment LXVIII. {Rana temporaria). — Ringer's solution; then extract of 

 S. sarmentosus in Ringer's solution (1 in 1000). (Plate IX.) 



Time in Minutes. 



Flow per Minute 

 in c.c. 



Time in Minutes. 



Flow per Minute 

 in c.c. 



Time in Minutes. 



Flow per Minute 

 in c.c. 



1 



2-9 



31 



1-5 



63 



0-7 



2 



30 



32 



1-6 



64 



0-6 



3 



3-0 



33 



1-5 



65 



0-6 



4 



2-9 



34 



1-6 



66 



05 



5 



3 



35 



1-6 



67 



0-6 



6 



30 



36 



1-4 



68 



0-5 



7 



2-9 



37 



1-4 



69 



0-6 



8 



3-2 



38 



1-5 



70 



05 



9 



3-0 



39 



1-4 



71 



05 



10 



2-9 



40 



1-5 



72 



0-5 



11 



2-9 



41 



1-4 



73 



0-4 



12 



2-9 



42 



1-4 



74 



0-3 



13 



3-2 



43 



1-4 



75 



0-5 



14 



3-0 



44 



1-3 



76 



0-4 



Strophanthus perfused. 



45 

 46 



1-2 

 1-3 



77 

 78 



0-4 

 0-3 



15 



3-1 



47 



1-3 



79 



0-4 



16 



3-0 



48 



1-2 



80 



03 



17 



2-7 



49 



1-0 



81 



0-4 



18 



2-2 



50 



1-0 



82 



0-2 



19 



2-3 



51 



1-1 



83 



0-4 



20 



2-4 



52 



1-0 



84 



0-2 



21 



2-4 



53 



1-0 



85 



0-3 



22 



2-1 



54 



09 



86 



0-4 



23 



21 



55 



1-0 



87 



0-2 



24 



2-0 



56 



0-9 



88 



0-3 



25 



1-9 



57 



10 



89 



0-3 



26 



1-8 



58 



0-9 



90 



0-2 



27 



1-7 



59 



08 



91 



0-3 



28 



1-6 



60 



0-7 



92 



0-2 



29 



1-7 



61 



0-8 







30 



1-7 



62 



0-6 







The frog weighed 31 grams before and 39 grams after this experiment — a gain of 

 8 grams. 



This strong solution of the extract produced a gradual diminution of the calibre 

 of the vessels and in 70 minutes they were almost occluded. But a solution of 

 digitalin twenty times weaker produces a more complete occlusion of the vessels in 

 less than 15 minutes, while, in the same time, the above solution of Strophanthus 

 extract causes only a moderate contraction. 



From these and other experiments it appears that dilute solutions of the extract 

 (1 in 25,000 and upwards) do not produce contraction of the blood-vessels of the frog; 

 stronger solutions (1 in 10,000) cause a very slight contraction, best seen where the 

 vessels are already dilated ; and very strong solutions (1 in 1000) have a moderately 

 powerful action in contracting the blood-vessels, though they are not occluded in one 

 hour. In comparison with digitalin, S. sarmentosus has a very feeble action on the 



