The Woburn Pot- Culture Experiments , 1913. 419 
that the addition of magnesia in excess would, on the contrary, 
have had a deleterious effect. 
The experiment strengthens the belief that where, on soils 
of this character, crops are found not to do well, the most 
probable cause is the high proportion of magnesia contained 
in them to the lime present, and that the remedy is to be 
found in the liberal application of lime until the magnesia 
is no longer predominant. 
III. The use of Sulphur as a Fertiliser. 
About a year ago the Agricultural Papers contained accounts 
of experiments conducted in France and in Germany which 
seemed to show that small dressings of flowers of sulphur 
increased the yield of certain crops. 
It was considered desirable, therefore, to make a trial of 
this at Woburn. The crops selected were mustard, rape, and 
clover. Shortly before sowing, flowers of sulphur equivalent 
to dressings of 3, 6, and 12 cwt. per acre respectively were 
added to the soil in which the crops were to be grown, the 
sulphur being mixed with the last 4 lb. of soil used to fill 
each pot. The experiment was conducted in duplicate. 
All three crops came up quite well, but from beginning to 
end there was no influence indicated, either in a beneficial 
or a detrimental direction, nor did the weights of the crops 
ultimately obtained show any practical difference, so that it is 
sufficient to state that, so far as these crops were concerned, the 
use of flowers of sulphur in amounts between 3 and 12 cwt. 
per acre was without any influence. 
IY. Experiments with Tomatoes , 1913. 
(i a ) Natural and heated' soil with addition of Lithium 
Phosphate. 
(b) Natural and heated soil with addition of Magnesia. 
The influence of lithium salts and magnesia has been 
already tried at Woburn on wheat with striking results, but not 
with other classes of crops. It was thought well now to study 
their influence on other plants such as the tomato. 
In addition, it was thought well, in view of recent work 
done on the heating of soils, to see if the effects of these 
additions differed according as whether a normal soil or one 
that had been heated was employed. The soil used in 1913 
was a made-up one composed of old rotted turf, sharp sand, 
and finely ground limestone. 
An analysis of it showed i 
t to 
contain : — 
Per cent. 
Organic matter . 
7813 
Lime . 
1-652 
Magnesia 
•396 
Nitrogen 
•259 
