071 the Bain and Drainage - Waters at Bothamsted. 
49 
{Plot 14), it is 24-43 lbs. ; with superphosphate of lime alone 
(Plot 11), 2G-73 lbs. ; and lastly, with ammonium-salts alone 
(Plot 10), 41-31 lbs. To such a great extent was the unused 
nitrogen of the manure washed out during the growth of the 
miserable crop on Plot 10, with the ammonium-salts alone, that 
there was only 1-03 lb. of that supplied accounted for in the 
<lrainage of the whole succeeding period from harvest to the next 
spring sowing. With this exception, the loss during the period 
subsequent to the removal of the crops, though very much less 
in actual amount, varies on the different plots much in the 
same order as previously. 
In the dry period of growth of 1880, on the other hand, the 
estimated losses from the manure were comparatively small. 
They were as before, the greater, the greater the supply of am- 
monium-salts : and greater with an equal supply of them used 
alone than when in conjunction with mineral manure. With 
the excessiv'e rain and drainage during the period of more than 
six months subsequent to harvest, the losses were much greater 
than during the period of growth ; and on the plots with the 
same amount of ammonium-salts, but different mineral manures, 
the losses varied exactly in the same order as during the wet 
period of growth of 1871). Thus, they were on Plot 7, with the 
ammonium-salts and the complete mineral manure, 3*65 lbs. ; 
on the intermediate plots, 7-60, 8-21, 9*44, 11-84 ; and on Plot 10, 
with the ammonium-salts alone, 17-51 lbs. 
Finally, the average amounts of loss per acre per annum 
|(over the two years) estimated to be due to the nitrogen of the 
manure, as shown in the last column of the Table, are with the 
same mineral manure and increasing amounts of ammonium- 
salts, 5*69, 11-63, and 25-82 lbs. accounted for in the drainage. 
And, with the same amount of ammonium-salts and different 
mineral manures, the average losses are^ — from Plot 7, with the 
complete mineral manure, 11-63 lbs. ; from the intermediate 
plots, 15-55, 17-95, 19-83, 22 81 ; and with the ammonium- 
salts alone, 33*24 lbs. 
Large as are these losses with the ammonium-salts spring 
sown, the loss is very much greater where, as on Plot 15, they 
were sown in the autumn, though with the same complete 
mineral manure as on Plot 7. The loss from the autumn-sown 
plot had been very great during the winter of 1878-9, and it 
was accordingly very much less than from the spring-sown plots 
during the period of growth and ripening of 1879. Receiving 
the ammonium-salts again in October 1879, the loss estimated 
to be due to the manure was 46*6 lbs. from the date of the 
preceding harvest to the time of spring sowing in 1880. This 
is more than ten times as much as during the same period from 
VOL. XVIII. — S. S. E 
