06 
French Experimental Fann at Vavjours. 
ivny veal value, it is indispensable that every other circum- 
stance connected with the plots, except the special object of trial, 
should be identical ; that is, that not only the soil should be 
uniform, but that the ploughing:, harrowing, manuring, and 
sowing be done simultaneously, since the difference of even a 
few hours may tell seriously on the results. 
" These considerati ons will account for the small number of 
experiments made, or at least reported, by the most enlightened 
advocates of agricultural improvement, and for their disregard of 
such experiments as have not been verified by repeated trials." 
The experiments commenced in the dry years 1857 and 1858, 
before the pumps and pipes were in operation, and before a 
supply of water for dilution had been secured, were in many 
respects inconclusive, and in some, unsatisfactory. 
Potatoes irrigated at the end of June in a scorching season, 
with undiluted sewage, were injured by the dressing. The 
plants were burnt up, and after a few days the leaves and small 
branches fell off ; new shoots sprang up from below, new tubers 
Avere formed, and the older ones died away. The two suc- 
ceeding crops of wheat and oats, however, profited largely by 
this misapplied dressing. Even on mangold, sewage undiluted 
did not produce a favourable effect in a hot season. 
For corn-crops the lesson was learnt that to avoid " lodging," 
an application of the sewage, some time liefore sowing, is 
desirable, a top-dressing in spring being fatal in a wet season. 
On the other hand, the application of sewage to first and second- 
crop hay gave the following satisfactory results. 
The Effect of Sewage on the Hay-Crop — chief y Rye- Grass. 
Green 
Produce. 
Hay. 
Percentage 
of Nitrogen 
in Hay. 
A First Cutting, May 9th : — • 
tons. cwts. 
tons. cwts. 
Hay dressed in winter with 10 tons ("nearly) of 
9 4 
3 0 
2 4 
0 14| 
1-94 
1-20 
A Second Cutting, Soptcmher Wth : — 
Aftermath dressed with 18 tons per acre 
6 10 
0 8^ 
1 cl 
0 2's 
2-90 
1-6(1 
The whole field had been dressed with sewage before the seed 
was sown ; but for this, the difference in the results would have 
been still greater. 
To com})lete the experiment M. Houzeau was requested, for 
the purpose of comparison with our own product, to analyse the 
hay of Paimbceuf, which is in high repute at Nantes, and that of 
