64 



Dr. H. M. Kyle. On the Action of the [June 25, 



lation, should contain about 0*001 per cent, of tannic acid. This latter 

 quantity of tannic acid should therefore be fatal within 2 hours, 

 whereas a solution ten times stronger took 4 hours, and one twenty 

 times stronger just the same time, viz., 2 hours. After making due 



Table II. — Experiments to Test the Power of Eecovery which the 

 Trout possessed after being immersed in various solutions for 

 some time. 



Strength and nature of 

 solution. 



Period 

 within which 

 it is fatal. 



Duration 



of ; 

 immersion. 



Recovery, or lapse of 

 time until death 

 occurred. 



20 per cent, of " fresh 

 extract" (0*2 per cent, 

 tannic acid, approx.) 



5 per cent, of " fresh 

 extract " 



5 per cent, do 



6 days 

 8 days 



1 per cent, do 



0*1 per cent, do., 4 days 

 old 



0*1 per cent, do., 

 old 



0*1 per cent, do., 

 old 



0*1 per cent, do., 

 old 



0*1 per cent, do., 10 days 

 old, and from which a 

 precipitate had he en 

 filtered 



0*01 per cent, do 



0*01 per cent, do 



0"01 per cent, of " fresh 

 extract." 2 days old 



0'2 per cent, of emulsion 

 minus volatile solid . 

 ( = 0*5 per cent, "fresh 

 extract " approx.) 

 As do., but 4 weeks later 

 0'01 pea* cent, of tannic 

 acid 



200 per cent, of tannic 

 acid. 



5 minutes . . 3 minutes I Recovery. 



10 to 30 



minutes 

 10 to 30 



minutes 

 1 to 1|- hours 

 If to 2 hours 



1\ to 2 hours 



l|to 4 hours 



1\ to 4 hours 



4 to 6 hours 

 4 to 6 hours 



hour 



1| hours 

 5 to 6 hours 



2J- hours 



3 minutes 

 15 minutes 



1 hour .. 

 1| hours 



li hours 



li hours 



f hour . . 



2 hours . . 



4 hours . 

 3a hours 

 4i hours 



40 minutes 



1 hour 

 4J hours 



2 hours 



Recovery. 



Death within 20 minutes. 



Death within i hour. 

 Death within | hour. 



Death within i hour. 



Death within li hours. 



Death within 3 hours. 



Recovery. 



Death within 10 minutes. 



Death within 1| hours. 



Death within If hours. 

 One specimen recov- 

 ered. 



Death within 10 minutes. 



Death within f hour. 

 Died 1 hour later. 



Died within 1 hour. 



allowance for variability in specimens, it seems certain from this that 

 the quantity of tannic acid, roughly estimated to be in the Spurge- 

 extract, is much less than the real quantity, or it may be that the 

 other components of the extract play a more important part than has 

 been credited to them. 



Some mention should be made of the peculiar phenomenon that the 



