120 



E. Wollny (1882-83) made seven series of experiments, in each 

 of which five or six tubs received daily different quantities of water, 

 except only that in the driest tubs extra water Avas given for the 

 first few days in order to insure the sprouting of the seeds, and 

 except, further, that in the experiments of 1882 the water was given 

 every second or third day instead of daily, w'hereby was brought about 

 the rather large variations in the moisture of the earth. The tubs 

 were shielded from natural rain, were of the same size, and had the 

 same Aveight of earth and aliment. Nothing is said as to whether 

 special manure or fertilizer Avas used, but only that all w^ere treated 

 perfectly alike except as to water ; the effect of manuring Avas shown 

 only in the case of Nos. 6 and 7 in that No. 6 w^as- treated like the 

 previous ones, Avhile No. 7 received a supply of mixed Peruvian guano, 

 superphosphate, and sulphate of lime, gypsum, or plaster equivalent 

 to 526 kilograms per hectare. Exact measurements were made 

 upon six plants in each tub in order to judge of the relatiA^e harA^ests. 

 An abstract of Wollny's measures is given in the following tables : 



EXPERIMENT OF 1882. 



EXPERIMENT OP 1883. 



"A variety of English or Windsor beans (Faba vulgaris) raised in Europe for feeding 



He concludes that, in general, the quantity of harvest is influenced 

 to an extraordinary degree by the quantity of available water and 

 much more than by any other factor of A-egetation. In general the 



