36 



were still green, and the cane had made a good growth in five months, 

 attaining a height of four and a half feet, but the basal leaves were 

 somewhat burned, thus exhibiting the injurious action of the salts 

 present. 



At location No. 3 the cane was weak and sickly looking, the leaves 

 being yellow and drying up. The total height of the cane after three to 

 four months growth was only 18 inches. We are therefore not surprised 

 to find .504% of bicarbonic acid and chlorine, with .641% in the first foot 

 alone; while the sulfuric acid radicle amounts to only .249%, which is not 

 more than one half of the other radicles, while in Nos. 1 and 2 the sulfuric 

 acid radicles was largely in excess. 



Location No. 4 presented about the same appearance as the foregoing ; 

 the cane was possibly somewhat worse than at No. 3, having grown to oniy 

 15 inches in three months and being gractically in a dying condition. 

 Correspondingly we find here the highest quantity of bicarbonic acid and 

 chlorine, viz. .661%, with .597% in the first foot; and at the same time 

 the sulfuric acid is quite low, only .179%. 



No. 5 had better cane. This had grown to a height of 2.5 to 3 feet 

 m three months, and looked much healthier then than the cane at locations 

 3 and 4. In accordance with these findings we have much less bicarbonic 

 acid and chlorine, only .293%. From this we might expect even better 

 cane than at station No. 2, but there we have a large quantity of sulfate 

 present, whereas in No. 5 it amounts to only .082%. 



There is another factor yet which must be considered in the inter- 

 pretation of the results, namely the height of the water level. In a large 

 part of the field the ground water comes quite near to the roots of the 

 cane, and the water alone will damage the cane, even if it be not salty. 



While the condition of the cane at the different stations can easily 

 be accounted for relatively, by the proportions of the salts present, the 

 absolute amount of chlorine and of bicarbonic acid that will permit the 

 cane to grow, is much higher than that found in the mineral soils discus- 

 sed before. We find that the cane at this place will grow well where the 

 chlorine content is .15%, the sum of bicarbonic acid and chlorine 

 amounting to .234% ; and that it even grows comparatively well at a place 

 where the chlorine is as high as .322%, and the sum of this and of 

 bicarbonic acid .45%. In the other area we had found the limit of chlor- 

 ine that the cane will endure 1o be between 0.04 and 0.11%. In the 

 present case there are evidently several factors at work which raise the 

 endurance limit of the cane towards salts beyond the point we had found 

 before. These factors have already been discussed at length, and we shall 

 only briefly recapitulate them here. The first of them is the protective 

 influence of sulfates against the injurious effects of other salts. The 

 second is the fact that calcium salts in general, and especially the sulfate, 

 are not only less harmful by themselves, but act as antidotes to the salts 



