238 



BOTANICAL GAZETTE 



[APRIL 



m the former. It is of course simply a matter of judgment how such 

 results are to be interpreted. Since barium and strontium are equi- 

 toxic in contemporaneous tests and since the same is true of barium 



— „ , J • • - • - - 



and masmesium 



o 



equitoxic. 



found 



In this table (V) the control figure is higher than that in Table IV. 



enzyme column. Just 



mcrease 



in the figures in the 



uniformit) 



test as a whole. For the sake of assurance another test was made, 

 and this gave practicaUy identical figures wath those in Table IV. 



m 



TABLE \I: Barium and magnesium in coniemporaneous test 



BARIUM 



Increase 



0.13 



0.12 



o.io 



0.07 

 0.06 

 0.03 



magn:esitjm 



128 

 64 



32 



16 



S 



o 

 o 

 o 







o 



10 



10 



10 



10 

 10 



1 



0.22 



0.,I2 



0.20 



0. 10 



0.18 



0.08 



0.16 



0.06 



0.16 



0.06 



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



In the work with ethyl but>Tate I found barium, st 



mamesium 



with ea 

 that be 

 sodium 



hich 



, ^„^.», ..i»j,l,ii itin.l,i ,■,K,^.^ ^^-^ 



In the foregoing tables there are some indications 

 itmm, and magnesium are more toxic than the 

 t, lithium group. On the other hand, the differ- 

 """" and magnesium are not so great. Thus, w/S 



Hthium in Table II aHows 0.09, while mf 16 of magnesium 



rV allows 0.07. 

 From the foregoin 



Igam, w/8 of lithium in Table III allows o.oj- 

 tables it would be impossible to say that the barium 

 group is more toxic than the sodium group on the equinormal basis. 



