258 
Groicth of Wheat. 
These results, adds M. Barral, speak for themselves. To 
obtain such an excess of produce for three successive years, if it 
has been done for three years, at a cost of from 8/. to 9/. per acre, 
is magnificent. 
Due allowance must, however, be made for the effect of the 
trenching, and of the subdivision into squares (and possibly for 
an unusual supply of humus), but otherwise it would seem that 
if a mixture of chemical manure, such as may be represented by 
nitrate of soda and phosphate of lime, with the addition of some 
potash, gave good results on such a soil as this, we may hope 
to find them generally effectual. The four principal elements 
are thus provided : other constituents are not less necessary, 
but in such small quantities that most soils have already a 
sufficient supply. 
The real importance of these minor constituents is well illus- 
trated by some experiments on the minute must-plant (Ascophora 
nigrans), conducted by Professor Raulin of Brest, as quoted by 
M. Barral. The Professor writes, " By a judicious choice of 
mineral substances, this plant may be made to develope itself in 
an artificial medium as rapidly as in its most appropriate natural 
fluids. Vegetation continues till one constituent runs short. The 
mineral substances requisite may thus be stated in their order 
of importance — Phosphorus, Potash, Magnesia, Sulphur, Man- 
ganese. These were supplied in the form of phosphate of 
ammonia, carbonates of potash and magnesia, sulphate of potash, 
and carbonate of manganese. If a fluid which contains all these 
substances will produce, say 20 grains of this plant, one that 
only differs from it by the absence of manganese will then only 
produce 5 grains in the same time ; if sulphur be withheld the 
product will only reach 2 grains ; if magnesia or sulphur, only 
1 grain ; if phosphorus, only half a grain. The required amount 
of these substances is very small, amounting to not more than 
2 per cent, of the plant's bulk of even phosphorus, which is most 
in requisition ; there are probably yet other substances which 
likewise enter into its constitution, but in still smaller degree." 
This illustration of the wide difference which subsists between 
manures which are practically complete, and those which 
fulfil the rigorous scientific conditions of completeness, may 
fitly close this notice of signal, if not exceptional, success obtained 
by the use of artificial manures on a light porous soil. 
5. — The Artificial Fecundation of Cereal and other Crops. 
Much interest and discussion has been excited of late in France 
by M. D. Hooibrenk's proposed methods of increasing the pro- 
duce both of corn and of fruit-trees, which have attracted the 
attention of the Emperor, have been investigated by a special 
