309 



when the wheat began to ripen, another analysis was made. 4. Seven 

 days later tbe wheat was cut and analysed; and, 5, fourteen days 

 after harvest the grain, thoroughly dried, was examined. This series 

 of analyses appears to establish the following ratios : 1 part of potassa 

 to 11 parts of gummy matter ; 1 part of lime to 43 parts of woody fiber ; 

 1 part of phosphoric acid to 2 parts of nitrogen in the albuminoid com- 

 pounds of the grain. 



The author dwells particularly on the ratio existing between the lime 

 and the cellulose or woody fiber. If lime be deficient, true woody fiber 

 will not be developed beyond this proportion, and the result will be that 

 the straw, consisting of loose cellular structure, will be disposed to fall ; 

 for this ratio appears to relate to the straw as well as to the grain. 



Tendency to " lodge " in grain has generally been attributed to a 

 deficiency of silica in an available form in the soil ; but these experi- 

 ments seem to controvert that theory; yet there is a link wanting to 

 secure the conclusion which the author reaches. If he had given us the 

 proportion of silica at every stage of the growth, as well as that of lime, 

 &c., we should have had an intelligible basis for a conclusion. In the 

 enamel of straw the silica exists as a silicate of lime and potassa, and 

 consequently must exist in definite proportions. 



Production of nitrogen compounds in soils. — In a French 

 journal {Comtes Rendus) we find a very interesting account of a series of 

 investigations relating to methods by which nitrates are formed in the 

 soil. Two tracts were selected, adjacent to each other in the commune 

 of Saussemesriel, and but a short distance from the sea-shore. One of 

 these tracts was covered with an oak forest, and the other, originally in 

 the same condition, had been in cultivation five years, and in that time 

 had received two dressings of quicklime of 10,000 kilograms per hectare, 

 each, (8,500 pounds per acre nearly.) This soil originally consisted of a 

 clay highly charged with iron, mixed with a considerable quantity of 

 fine gravelly sand derived from the Silurian sandstones. 



The samples were selected after a long drought in the month of Au- 

 gust, and consisted of both surface and subsoil, which were examined 

 separately. On treating these soils with dilute acid it was found that 

 the forest soil was entirely destitute of lime, while the cultivated field 

 showed 1.583 per cent, of lime in the surface-soil and O.G09 in the sub- 

 soil. 



A portion of soil from each of the fields (35 kilograms, or 72 pounds,) 

 was subjected to percolation for the purpose of ascertaining its soluble 

 contents. This solution was found to contain in 950 cubic centimeters, 

 as follows : 



Forest. Cultivated 

 field. 



Millig. Millij. 



Organic matter 155 70 



Silica 35.5 29 



CMorine 600.5 207o 



Sulphuric acid 5. 6 32. 6 



Nitric acid 707 



Phosphoric acid and iron 5.7 5. 8 



Potassa 69 25.8 



Soda 287.7 180.7 



Magnesia ....68.6 90 



The remarkable feature in the above table is the entire absence of 

 nitric acid in any combination in the forest soil, while that from the cul- 

 tivated field shows a fair proportion, and yet no nitrogenous substance 

 had been used as manures on that field. 



