He carried out a number of magnetic investigations which resulted in the discovery of many interesting phenomena, some of which have been rediscovered by others; they related among other things to the effect of mechanical strain on the magnetic properties of the magnetic metals, to the relation between the chemical composition of compound bodies and their magnetic properties, and to a curious parallelism between the laws of torsion and of magnetism.
These vary considerably in completeness with its age; in its younger parts the outer cells wall undergoes the change known as cuticularization, the material being changed both in chemical composition and in physical properties.
But it is worthy of special attention that the mere chemical composition of agricultural and garden soils is, as a rule, the least important feature about them, popular opinion to the contrary notwithstanding.
However, until more is known of the exact chemical composition of naturalas contrasted with agriculturalsoils, and until more is known of the physiological effects of lime, it is impossible to decide the vexed question of the relation of limeloving and lime-shunning plants to the presence or absence of calcium carbonate in the soil.
So much, indeed, does the character of the herbage vary from plot to plot that the effect may fairly be described as kaleidoscopic. Repeated analyses have shown how greatly both the botanical constitution and the chemical composition of the mixed herbage vary according to the description of manure applied.
