46 TOXIC LIMITS OF ALKALI 



of sodium carbonate, but neither they nor wheat were 

 injured in 5000 parts per million of sodium bicarbonate. 

 According to this author the highest strength of sodium 

 chloride endurable by the cereals was 5000 parts per mil- 

 lion, by legumes 3000 parts per million, and by rape 1000 

 parts per million. Jarius, as quoted by Kearney and 

 Cameron (14), reports a stimulating effect on seeds of 

 wheat, rye, rape, maize, beans, and vetch in a solution 

 containing 4000 parts per million of sodium chloride. 

 Storp, as quoted from Kearney and Cameron (14), found 

 this salt to stimulate germination in solutions as strong as 

 100 parts per million. In his work with solutions of sodium 

 chloride in concentrations ranging from 1250 to 50,000 

 parts per million, Coupin (6) found the toxic limits for 

 wheat to be 18,000 parts per million, of lupine 22,000 parts 

 per million, of maize 14,000 parts per million, of peas 12,000 

 parts per million, and of vetch 11,000 parts per million. 

 In this author's experiment the endurance of the plant as 

 a whole to the solution was taken to indicate the limit, 

 whereas with some of the others the death of the root or 

 some other part is sometimes taken to indicate the injury 

 to the plant. He found the toxic limits for seashore plants 

 to be several times that for the crop plants mentioned 

 above. Nessler, who is quoted by Hicks (12), states that 

 hemp seed was injured in germinating by 2500 parts per 

 million of sodium chloride, clover by 5000 parts per mil- 

 lion, and wheat by 10,000 parts per million. Rape seed 

 was found to resist sodium chloride, potassium chloride, 

 calcium nitrate, sodium nitrate, and potassium sulphate 

 in concentrations as high as 5000 parts per million, but 

 the vitality of wheat, rye, maize, beans, and peas was 

 seriously injured when using solutions as strong as this (12). 

 Sodium chloride had a stimulating effect. 



