100 YEARS AGO

Our present state of civilisation has of necessity resulted in an annual increase in the amount of capital borrowed by man from the store of energy accumulated by our earth in bygone times, and the diversion of this capital to uses for which the world's annual income of solar energy was formerly deemed adequate. An instance of this tendency is afforded by the experiments of Dr. Selim Lemström, of Helsingfors, on the uses of electricity in stimulating the growth of cereals, vegetables and other plants... The investigation seems to have been suggested in the first instance by an attempt to connect the luxuriant growth of plants in high latitudes with the influence of electric currents associated with the Aurora Borealis. The experiments showed that for plants growing on arable land of medium quality an increase of 45 per cent. in the crops is obtainable; but the better the field is ploughed and cared for the greater will be the increase. On poor soil the effect is trifling. Certain plants, such as peas, cabbages and turnips, only lend themselves to electrical treatment after being watered. It is, however, injurious to most, if not all, plants to submit them to the influence of electricity in hot sunshine... A further suggestion is that we have here an explanation of the needle-shaped leaves of coniferous plants which are well adapted to facilitate the passage of electricity, or in common parlance, “attract electricity.”

From Nature 24 April 1902.

50 YEARS AGO

Crystalline penicillin (sodium salt) was added at the rate of 12.6 gm. per ton to a standard turkey-rearing mash... The experiments briefly summarized show that the addition of small amounts of penicillin to the diet of growing turkeys not only produced a significant increase in growth-rate but also that it appeared to have a profound effect in stimulating metabolism, tiding chicks over a critical period of susceptibility to chilling and other non-specific causes of mortality during the first few weeks of life. Rate of growth and mortality during rearing are factors of primary importance to the turkey industry and largely determine the profitability of the undertaking... Its administration to birds destined for the table within the shortest possible time would appear to be strongly indicated.

From Nature 26 April 1952.