244 



BOTANICAL GAZETTE 



[APRIL 



TABLE XIII: Mercury and silver in contemporaneous test 



MERCURY 



m 



Water 



65536 

 32768 



16384 

 8192 



4096 



Reagent 



Control 



Enzyme 



Increase 



O 

 O 



o 



o 



o 



.00 



.00 



.00 



■05 



.10 



o 

 o 



10 

 10 



o. 10 



O.IO 



o. 10 



0-13 



0.18 

 0.15 

 0.15 



0.12 



o. 10 



0.13 



0.08 



0.05 

 0.05 



0.02 

 0.00 

 0.00 



SILVER 



Enzyme 0.05 per cent. Incubation 5 hours at 40 C. 



In this test mercury is more toxic than silver, even on the equi- 

 normal basis, though the diflferencc here is not nearly so great as was 

 found with ethyl butyrate. Of course the greater concentration of the 

 enzyme used here introduces a factor in addition to that of the diflfcrent 

 zymolyte. Mercury in comparison with silver is Hke copper in com- 

 parison with zinc in regard to precipitating power. The pomt o 

 total inhibition is close to that of the first appearance of a precipitate; 



m 



131072 



65536 

 32768 



16384 



8192 



4096 



131072 



65536 

 32768 



16384 

 8192 



4096 



TABLE XIV 



MERCURY 



Control 



Enzyme 



o. 



o. 

 o. 



o. 

 o. 

 o. 



10 



10 

 10 

 10 



10 



13 



015 

 0.15 



0-13 



O.IO 



O.IO 



0.13 



SILVER 



Increase 



0.05 

 0.05 

 0.03 

 0.00 

 0.00 

 0.00 



0.03 

 0.03 

 0.03 

 0.02 

 0.02 

 0.00 



Enzyme 0.05 per cent. Incubation 5 hours at 40° C 



