39 6 



BOTANICAL GAZETTE 



[may 



surfaces, however, is not so readily obtained. It may be that adsorp- 

 tion of toxins and adsorption of vapors and gases are subject to the 



same conditions (n). 



measurements 



may 



for the calculation of the surface of these bodies. A curve showing 

 how the adsorption data are related to the surface presented by the 

 grains of the different soils used, though of interest, is not a ques- 

 tion at issue in this discussion, but it is hoped to continue this problem 



manner 



The precaution was taken to allow contact between the solution 



minutes 



minimum 



___ ^ iterials (3) and the possible 



action of the solution upon the solids. The amounts used in each 

 case, and the effect of these insoluble substances on the toxic action 

 of bog water collected January 30, 1909, are given below in Table I\ . 

 The transpiration data cover a period of fifteen days and are for six 

 wheat plants in each solution. 



TABLE IV 



Adsorption of bog toxins by insoluble substances 



Solution 



Transpiration in gram ^ tt . tt0n 



SIX WHEAT SEEDLINGS IN EACH SOLUTION 



I. 

 2. 



3- 



4. 



5- 

 6. 



8. 



9- 

 10. 



11. 



12. 



!3- 



14. 



16. 



18. 

 19. 

 20. 

 21. 



Bog water 4oo cc , untreated 



Bog water 4oo cc , filtered 



Bog water 4oo cc + i5 cc Si0 2 (coarse) . 

 Bog water 4oo cc -f 25 cc Si0 2 (coarse) . 

 Bog water 400°° + 5o cc Si0 2 (coarse) . 

 Bog water 4oo cc -f- I5 CC Si0 2 (fine) . . . 

 Bog water 400°° + 25 cc Si0 2 (fine) — 

 Bog water 4oo cc + so cc Si0 2 (fine) — 



Bog water 4oo cc + I5 CC Kaolin 



Bog water 4oo cc + 25 cc Kaolin 



Bog water 4oo cc + 5o cc Kaolin 



Bog water 400°° + 150°° Kaolin 



Bog water 4oo cc 4- I5 CC CaCo 3 



Bog water 4oo cc + 25°° CaCo 3 



Bog water 400" 4- 5o cc CaCo 3 



Bog water 4oo cc + 15CC SiC (fine) 



Bog water 4oo cc + 25 cc SiC (fine) 



Bog water 4oo cc + 5o cc SiC (fine) 



Bog water 4oo cc + 15** C. (humus). . . 

 Bog water 4oo cc + 25 cc C. (humus). . . 

 Bog water 4oo cc + i5o cc C. (humus). . . 



* 5 plants in culture. 



