237 



BOTANICAL GAZETTE 



[APRIL 



TABLE IV: Barium and magitesium in contemporaneous test 



BARIUM 



magkIesium 



128. 



64. 



32- 

 16. 



8. 



o. 10 

 o. 10 

 o. 10 

 o. 10 

 o. 10 



O. 22 



o. 20 



0.18 



o. 17 

 o. 16 



0.12 



o. 10 



0.08 



0.07 

 0.06 



Enzyme 0.05 per cent. Incubation 4.5 hours at 40'' C. 



bition seems to be impossible for this concentration of the enzyme 

 as w/4 of the salts is almost saturation at room temperature. In this 

 test the two salts are certainly equitoxic. 



TABLE V: Barium and strontium in contemporaneous test 



BARIUM 



STRONTIUM 



Enzyme o . 05 per cent. Incubation 5 hours at 40" C. 



In this test the two salts are certainly equitoxic. Comparison with 

 Table IV however shows inconstancy. Thus, w/8 of barium in 

 Table IV allows 0.06 as compared with 0.03 in Table V. On the 

 other hand, in both cases, w/128 of barium allows uninhibited activ- 

 ity. Again, the figure indicating full activity in Table IV is less than 

 that in Table V, and yet w/8 barium inhibits more in the latter than 



