347 



The percentages of protein were in general decidedly larger in tlie 

 jdaiits Avhicli liad nitrate of soda than in those Avhicli wer<i unmannred. 

 Exceptions to this rule, however, were tbuiid with the cereals in 188G, 

 which season was wet, while in 1885 and 1887 it was relatively dry. 

 The average daily rainfall dnriiig the growing mouths of May, .lune, and 

 July was, in 1885, ]. SO nun ; inl8S(>, ii.(j()inni; in 1887, 1.7.j)nni. The fol- 

 lowing figures give the differences found by subtracting the percentages 

 of protein in the unnumured plants from those in the corresponding 

 plants treated with nitrate of soda. It is to be renu-mhercd, ho\ve\ er, 

 that the analyses were made of single and not of duplicate samples, and 

 that the figures in this table, as in the one just preceding, retx^r to the 

 airdry substance. It is not impossible that deteiininations of water 

 and calculations of weight and comi)osition of water-free substance 

 would have made some changes in the relative proportions, though it 

 seems hardly probable that the tenor of the results would have been 

 materially alteied. 



Increase (-{-) or decrease (— ,) in percentages of protein in produce with nilralc of mida as 



compared with no manure. 



Cereal. 



Barley 

 AVlieat 

 Gats . . 

 Peas.. 



1885. 

 Relatively dry. 



Grain. Straw, 



-f2.6 

 +2.6 

 +2.1 



+2.8 



+0.6 

 +0.8 

 +0.7 

 +1.7 



1880. 

 Relatively wet. 



Grain. Straw. 



+0.2 

 -0.4 

 -0.9 



+ 2.4 



-0.1 

 +0.7 

 -0.3 

 + 0.8 



1887. 

 Relatively dry. 



Grain. Straw 



+2.6 



+;:.2 

 +1.5 

 +"2.8 



+ 0.9 

 +1.9 

 +0.4 

 + 0.4 



Average of 

 three .seasons. 



Grain. Straw. 



+1.8 



+ 1.8 

 +0.9 



+ 2.7 



4 0.5 

 + 1.1 

 +(1. :{ 

 + 1.0 



(4) The percentage of ash was apparently not affected by the phos- 

 phate and potash salt in any of the plants nor by the nitrogen in the 

 peas, but in the cereals it was lower with the nitrate of soda than with- 

 out it. 



(5) As regards the relative development of the different organs, the 

 water supply seemed to have more influence than the fertilizers. When 

 the rainfall was large the stems and leaves were developed at the 

 expense of tbe seed. 



(6) The amount of water whicb escaped by evaporation from the soil 

 and by transpiration through the plants during the growing season, 

 varied greatly with the seasons. From the observed results Dr. Wohlt- 

 mann has made computations of what he regards as normal (luantities 

 in liters per x)lant and jier kilogram of dry substance. These, with the 

 estimated amounts per hectare in cubic meters for each of the three sea- 

 sons, are given in tabular form herewith. The quantities are for the 

 periods of vegetation of a little over 3 months. 



11233— Xo. 5 6 



