462 
Number of contr. 
per min. 
nn 
de le 
726, 7 lake hs Number of contr. | 
i 
25 , 30 per min. 
20. 25 
15 20 
10 15 
Orr Pas: a6 8 02 03 BA GEN 
Diaer. V. liagr. Viz 
Decrease of the NaCl%/,, the osmotic pres- Decrease of the NaCl®/, the osmotic pres- 
sure being kept constant by cane-sugar. Effect sure being kept coustant by cane-sugar. Effect: 
upon the frequency. CaCl, 6 aq. = 0,01°/. on the frequency. CaCl, (without water of 
crystallisation) = 0,01/. 
Sy pmm 
ENANDNDPAL ITS Kel MANY \\ AN NAAN An 
oT te eel -—— — 
Fig. 4. Effect of NaCl. At R change from NaCl 0,1 '/o to NaCl 0,30/,. Effect 
after 5 minutes. At T of the same experiment, change from NaCl 0,3%, to 
ordinary Ringer. Effect after 5’. Time marked in half minutes. 
strongly decreased between 0.3°/, and 0.1 "/, (fig. 4). To what extent 
the increase must be attributed to the cane-sugar or to the withdrawal 
of NaCl as such, cannot be stated with certainty. | 
On the tonus | have only a few observations in two experiments. 
In both experiments it increased when NaCl was withdrawn, whilst 
a return to the original quantity of NaCl caused a decrease. 
Inerease of osmotic pressure by cane sugar and urea. 
Glucose was precluded, its action on the heart being too specific. 
This is aceording to most authors not the case with cane-sugar, 
and urea was taken because, in contrast with other tissues it is 
marked, according to Lussanna, by a certain osmotic activity as 
regards the heart. 
A comparison of the diagram VII and VIII brings to light the 
creat difference: cane-sugar decreases the frequency, urea does not 
alter it in the least. In order to be absolutely certain we have sub- 
