100 YEARS AGO

The treatment of disease by light.

The drawbacks to the treatment are, first, the length of time which a severe case takes, and, secondly, the cost. Not only is there the cost of the electric light and the necessary maintenance, but every patient has to be attended by a nurse. At the London Hospital it has been found that it costs about 400/. or more a year to run one lamp, so that the light department there necessitates an expenditure of 1200/. a year. It is, therefore, gratifying to find that Mr. Alfred Harmsworth has come forward and endowed one lamp by a munificent gift of 10,000/.

From Nature 11 July 1901.

50 YEARS AGO

Normally, when an observer is making colour comparisons, he is in the erect position and with normal vision both eyes exhibit similar colour sensitivities. I have observed, however, that if the observer is in the prone position lying on one side, a gradual difference between the colour response of the two eyes develops. After a few minutes the lower eye becomes markedly red-sensitive compared with the upper eye. If now the observer lies on his back, the two eyes gradually return to equality of colour response. By turning on to the opposite side, the eye formerly red-sensitive will be uppermost and will then gradually develop blue-sensitivity compared with the lower eye.

From Nature 14 July 1951.