122 Scientific Intelligence. 
rams of nitre in a cubic litre of soil. On the 29th of the month, 
twenty rainy days, the same quantity of the same soil contained only 18 
grams of nitre. The greater part had been dissolved out of the super 
ficial soil. oe 
Some specimens of forest-soil, in a state of nature, furnished no indica 
tion of nitrates: others gave 0°7 and 3:27 grams of nitre to the cubie 
m 
tre. 
The soil of meadows and pastures afforded from 1 to 11 ms of 
— of nitre to the cubic metre. To the latter much calcareous matter 
ad been added. 
The soil of a conservatory, from which the nitrates would not be 
washed away by rains, contained 89, or 161, and some rather deep soil 
The sources of the nitre are not difficult to understand when we re 
that a manured soil, especially a calcareous one, 4s just in the condi 
an artificial nitre-bed. The ultimate result of the decomposition of 0 
nary manure is a residuum of alkaline and earthy salts, phosphates, 
all-essential to productive vegetation 
The soluble matters washed out of the soil are to be sought in a 
water. River and spring waters therefore act as manure by the silex ane 
alkali, the organic matter, and the nitrates which they hold. The ; 
waters poorest in nitre of those examined contained from 0:03 to 0° 
milligrams of nitre to the litre; the richer ones from 11 to 14 gram 
in the cubic metre. Seine 
to river-water; the Vesle in Champagne held 12 grams, the 
at Paris 9 grams the cubic metre. These were the richest. The 
by the Mississippi, the Amazon, and by every great continental river; 
how active, beyond all ordinary conception, must the process of NINN 
tion be over all the land; and how vast the supply of assimilable nitroge? 
for the use of the vegetation | . ale 
10. Action of foreign Pollen upon the Fruit.—-In the last number sane 
Journal, p. 443, some facts were referred to which led to the suppos! an 
that pollen applied to the stigma may exert some specific action Uj “the 
ovary itself, independent of its action upon the ovules determining ! 
