By SIR ARTHUR HENRY DOWNES, M.D.
BEING told that readers of “THE HOMOEOPATHIC WORLD” may be interested in a short account of some simple experiments made by my late friend T.B. Blunt, M.A. (then County Analyst for Shropshire) and myself some fifty-five years ago, I embark on a brief narrative shown of technical detail:.
Looking back over this half-century I note the greatly augmented health and the bronzed skins of a sun-loving people and I marvel at the stride in our knowledge of sunlight and of radiant energy beyond our vision.
In 1877, though photography was extending our knowledge beyond the visible spectrum we did not dream of “alpha” or “beta” or “gamma” rays. We had, of course, a conviction that sunshine gave health. There were old proverbs “Where the sun does not enter the doctor comes” and the likes. Beyond some old trials on animals or plants in darkness or in light, or under glass of differing colours, practically nothing was really known.
We were sure that there was in Light a Life-giving quality which lay at the root of all our being. So sure indeed that, when in the early seventies there was fierce contention between scientific men who claimed that they had produced living organisms newly evolved by “spontaneous generation” from certain broths or infusions, Prof. Tyndall, who hotly opposed them, took with him to Alpine heights samples of these broths or infusions. He did so with the chivalrous desire to give the utmost help that the purest and intense sunlight could render to the evolution of Life if it were possible that his opponents claim were true.
But now arose a crux: Pasteurs great work had fixed our minds on “germs” and at that time most of the germs known to us were of evil reputation, breeders of disease or of putrefaction. One of us was thus puzzled by reasoning: “Light is life-giving and health-giving; but the germs of disease are living entities and should therefore flourish in Light.” How to reconcile this? With this came the commonplace reflection that some lowly organisms seem certainly to flourish in the dark; what about the moulds and mildews of our jam stores or boot-cupboards? This did not seem to fit in with received doctrine. So the best thing to do was to put it to the test.
This was essentially a simple affair; a number of test-tubes were partially filled with a clear liquid which, as usually stored, would in a day or so become putrid with teeming germ life unless previously sterilised by boiling. Half of the number of these test-tubes were placed outside a sunny window; the outer half stood alongside them but were shielded from the light by paper or lead-foil wrapping.
At the same time it was ascertained that there was no material difference in the temperature of the liquid in the two sets. Any difference between them was an affair of Light as distinguished from Heat. In a single night, if the weather was warm, the shielded liquids were already clouded by germ growth. Their sun-lit companions remained clear and translucent: indeed the liquid employed became even more brilliant in appearance.
These definite results were so elementary that we wondered if they could be new to science. To settle the point. I went straight to Professor Huxley whom I found at his official desk. He received me, a perfect stranger, with great kindness. I asked if he could tell me if anything was known of the effect of light upon these germs Bacteria? “It is well-known,” replied Professor Huxley, “that they can live in the dark.” Thereupon I triumphantly produced the samples I had brought with me the one tube thick and putrid with the germs bred in darkness, the other clear as crystal, the living elements which it had originally contained “blasted with the excess of Light.”
I told him how the tubes had stood side by side with but the one difference narrated above. In a few minutes it was settled that an account of the experiment should be submitted to the Royal Society. In due course I had the temerity to attend the meeting and, in response to invitation, actually to speak! Fortunately I had no criticism to answer. I forget if Professor Tyndall said anything but for a time he was reluctant to accept conclusions which did not well harmonise with the Alpine excursion! In no long time, however, he amply confirmed them.
One thing I recall to mind, quite irrelevant to the present narrative, but which, added to the kindly reception given to such a youngster as I then was helped to set me at my ease. A very eminent mathematician was speaking on the Tides of the Mediterranean, but forgot his geography, particularly as to the name of the place opposite to Gibraltar. The Society endeavoured to help and for a few minutes there was a guessing contest, some favouring Algeciras, most plumping for Tangier, until it transpired that it was Ceuta!.
Of course there was much more work lying before Blunt and myself but I must not weary my readers with details. Suffice it to say that we found that the presence of oxygen was necessary for Light to act thus destructively on these elemental forms of Life. There may have been less oxygen in our atmosphere when, as we may imagine, the first lowly organism emerged from the ooze, but its unshielded protoplasm would soon have needed some protective device and the most marvellous device is the development of the green colouring matter of the vegetable world, with its laboratory on which all existence depends. Yet even chlorophyll may be destroyed by excess of Light. The protective devices of Nature are infinite and we cannot probe all.
Later on I tested many kinds of germs. To my astonishment the tubercle bacillus succumbed in twenty minutes and the spores of anthrax in two hours of brilliant sunshine. The destruction of the spores was the more amazing because they resist even boiling heat. On the whole I should say that the evil germs are more sensitive than the harmless, although there may be varied opinions on the point of harmlessness as to the resistance of the little wine-yeasts on the sun-kissed grape!
In conclusion I may perhaps mention as a practical point that we very soon found that ordinary window-glass cut off much of the germ-killing power of Light; so also did a layer of liquid. This last was probably one reason why we had not been anticipated in this work. There were in fact certain small difficulties of technique, for the era of cultures on solid media had not yet come.
With regard to windows, the matter is of much importance to the comfort and health of indoor workers, and in passing recently through London I wondered how far the extensive glazing of some of the newer office-buildings will work out. As Tyndall showed and all may learn from an ordinary greenhouse, common window glass, while cutting off the ultra-violet rays, acts as a veritable trap for heat, good for plants but not so good for human beings.