282 Agricultural Education Exhibition , Bristol , 1913. 
continues under the ordinary course of treatment, such as haying 
or grazing as circumstances warrant. There was also to be 
seen in this bay a most useful method of keeping crop records, 
by means of which the previous cropping of any portion of the 
farm can be ascertained at a moment’s notice. Portions of soil 
taken from the field trials at Ware showed to interested visitors 
the result of some years work on the extermination of the 
wild onion. It has been known for some time that certain 
chemicals would kill the bulbs growing in the top layer of 
soil, but the bulb is also found growing some three or four 
inches down. By better drainage of the soil, and by the 
inclusion of deep-rooting grasses in the grass mixture, much 
can be done to eradicate this weed, for no trace of it could be 
found in the specimen shown. This is without doubt an 
important piece of work, and it is to be hoped that it may be 
brought to the notice of all farmers of strong land. 
Another interesting exhibit dealt with the question of how 
long can we go on spraying our crops with solutions of sulphate 
of copper before the accumulations begin to show the toxic 
effect that copper salts are known to have on vegetation. 
Wheat was shown growing in pots, to the soil in which 
successive and increasing quantities of copper sulphate had 
been added, and it was not till amounts had been used equal to 
*05 per cent, of copper that any poisonous action was noticed, 
whilst judging from the appearance of the plants a matter of 
•01 per cent, copper seemed to be stimulative rather than 
toxic in its action. If 10 cwt. of bluestone were used to an 
acre there would be -01 per cent of copper in the soil, assum- 
ing that it would be affected to a depth of 9 in., and when it is 
remembered that a spraying mixture for charlock for instance 
is 40 gallons of 4 per cent, solution per acre, it is obvious that 
there is little to fear from copper poisoning of plants. 
Further work illustrating the effect of lime and m agnesia 
on the wheat plant was shown ; in one case lime was added to 
a soil that was known to contain a considerable amount of 
magnesia, and in the other magnesium oxide had been mixed 
with the soil. The results were very marked, and not the 
least remarkable part of the experiment was the influence 
exerted on the type of grain grown. Diagrams and pictures 
together with samples of corn and roots completed the exhibit 
and . in a second bay the publications of the Society were 
obtainable, as well as diagrams of various insect pests, whilst 
there was also a fine set of prints showing the different stages 
m the life of the wheat plant. 
Rothamsted Experimental Station.— This station sent an 
interesting collection of water cultures, showing the effect of 
foods and poisons on plants. Manganese, zinc, copper and 
