Comparative Effects of different 3fanures on Grass Lands. 645 
tlie land ; v/licn tliis is clone, the air finds free access throngli the 
organic refuse matter, and converts the nitrogenous portion of it into 
nitric acid, which is fixed by the earthy matter. We thus obtain 
in a compost-heap which has been kept some six or eight months a 
considerable portion of nitre ; and this has an excellent efiect on the 
herbage, particidarly on plants of the cereal tribe. By such means 
WQ may make the best of the worst description of pastm-e. 
Very briefly recapitulating the main points which I have endea- 
voured to bring out in this lectiu'e, I would remind my audience, first, 
that ammoniacal mamu-es have a special efiect in jn-oduciug a luxm-iant 
development of the cereal tribe of plants ; and that if the necessary 
amount of mineral matter is present, they largely increase the general 
produce. We have seen, further, that mixed mineral manures com- 
posed of phosjihoric and alkaline salts increase the leguminous produce; 
that the sole application of ammoniacal salts ought to be avoided ; 
and that it is best to have a fair mixtui-o of both mineral and ammo- 
niacal matters. Again, we have seen that there are soils vrhich are 
very grateful for a liberal expenditm-e of money, this being the con- 
dition of a great deal of the grass land of England at the present time. 
Though an indolent farmer may find an excuse in the fact that there 
are hero and there soils v^'hich cannot be improved, nevertheless 
pastures may be improved by a judicious outlay on manuring substances 
to an extent, and with a profit, of which few people have any idea. 
Lastly, we have seen that on the poorest description of gi'ass land, 
waste matters, the droppings of cattle, earthy substances, and such 
like, may be conveniently made into a compost manm-e, which on 
such soils will produce a very excellent effect. 
Sir Geokge J enkinson asked whether the different samples exhibited 
were each pulled up in one handful from one iiarticular si^ot in the 
trial field, or whether the bimdles were made up of selected grasses 
culled from various parts of the field. 
Professor Voelckee replied that the specimens represented as nearly 
as possible the general character of the experimental plots. 
Mr. Thompson said, having had an opportunit_y of seeing the expe- 
rimental plots on the previous day, he could corroborate that statement. 
The plots consisted of an acre each, and if there was one thing more 
striking than another, it was the uniform character of the herbage 
over each of the plots. There might bo some differences arising from 
the movements of the sheej) by which the after-crop is always eaten off, 
but the exceptions owing to that cause were confined to a very small 
proportion of the plots. On the whole, the herbage of the several plots 
presented a very distinct outline. When revisiting these plots (which 
lie had frequently examined before), after an interval of two yeai's he 
had been particularly struck mth the development of the particular 
characters of herbage on the different plots which had been treated in 
a particular manner, for a succession of years. It showed how much 
they had at their command the growth of the herbage on land which, 
at all events, was not what they would natm-ally call good grass land. 
