Causes of Fertility or Ban-enness of Soils. 207 
to the absorj)ti()n of too much carbon in proportion to silica, 
makinjj the straw soft and flaggy and unable to bear the ripening 
ear. Peat bogs that have been reclaimed by draining and marling 
are found better adapted for pasture than arable farming ; the 
most approved method of management being to cultivate for the 
first few years till the humus is thoroughly decomposed, and 
then lay down with permanent grasses, the feeding of which firms 
the land and in time produces a valuable herbage. In most soils 
we find a deficiency of vegetable matters, and the farmer is anxious 
to supply as much as possible, in the form of farm-yard manure, 
sea-weeds, and decayed rubbish of all sorts ; such manures act as 
direct food and mechanically in keeping the soil open. We should 
strongly advocate the occasional application of small dressings of 
lime between the manurings, because it would come into contact 
with undecomposed portions of manure — humus in fact which 
otherwise might lie dormant in the soil — causing the formation 
of a further supply of carbonic acid for the roots of plants. 
In concluding this paper the writer feels it necessary to apolo- 
gise for the scanty and imperfect information he has been able to 
produce on several points, and to crave the indulgence of the 
reader generally in consideration of the difficulties with which 
this subject abounds. The patient and oft-repeated experi- 
ments of the scientific investigator, added to a careful record of 
facts by the practical cultivator, will in course of time add much 
to our present meagre knowledge of the real causes of barrenness 
and fertility in soils. 
Deene, Northamptonshire. 
XII. — Report to the Right Honourable the Earl of Leicester — on 
Experiments conducted by Mr. Keary on the Groioth of Wheat 
upon the same land for four successive years, at Holhham Park 
Farm. By J. B. Lawes, F.R.S. 
It has been proved by careful experiments that wheat can be 
grown for several years in succession upon "heavy" land, and 
that by means of a proper supply of certain chemical substances, 
an average or even full agricultural crop, according to the season, 
may be obtained each year with certainty. But it is believed 
that there have been no experiments of the same kind carried on 
with accuracy and on a large scale, upon soils other than those of 
a comparatively heavy character. It is, indeed, not many years 
since the practice of removing from any land more than one 
