182 HOW CROPS GROW. 



list of necessary ingredients of maize, and from not yet 

 fully described experiments doubts that it is necessary for 

 buckwheat. 



Leydhecker, in a more recent investigation, has come to 

 the same conclusions as Nobbe & Siegert, regarding the 

 indispensableness of chlorine to the perfection of buck- 

 wheat. (Vs. St., VIII, 177.) 



From a series of experiments in water-culture, Birner 

 & Lucanus, ( Vs. St., VIII, 160,) conclude that chlorine 

 is not indispensable to the oat-plant, and has no specific 

 effect on the production of its fruit. Chloride of potassium 

 increased the weight of the crop, chloride of sodium gave 

 a larger development of foliage and stem, chloride of mag- 

 nesium was positively deleterious, under the conditions 

 of their trials. 



Lucanus, ( Vs. St., VII, 363-71,) raised clover by wa- 

 ter-culture without chlorine, the crop, (dry,) weighing in 

 the most successful experiments 240 times as much as the 

 seed. Addition of chlorine gave no better result. 



Nobbe, (notes to above paper,) has produced normally 

 developed vetch and pea plants, but only in solutions con- 

 taining chlorine. Knop, still more recently, (Lehrbuch 

 der Agricultur- Chemie, p. 615,) gives his reasons for not 

 crediting the justness of the conclusions of Nobbe & 

 Siegert and Leydhecker. 



Until further more decisive results are reached, we are 

 . warranted in adopting, with regard to chlorine as related 

 to agricultural plants, the following conclusions, viz.: 



1. Chlorine is never totally absent. 



2. If indispensable, but a minute amount is requisite in 

 case of the cereals and clover. 



3. Buckwheat, vetches, and perhaps peas, require a not 

 inconsiderable amount of chlorine for full development. 



4. The foliage and succulent parts may include a con- 

 siderable quantity of chlorine that is not indispensable to 

 the life of the plant. 



