The observations lately made by a Chancellor of the Exchequer about an attempt to put salt on a bird’s tail remind me of my first attempt to deal experimentally with a popular superstition. I was a very trustful little boy, and I had been assured by various grown-up friends that if you place salt on a bird’s tail the bird becomes as it were transfixed and dazed, and that you can then pick it up and carry it off. On several occasions I carried a packet of salt into the London park where my sister and I were daily taken by our nurse. In vain I threw the salt at the sparrows. They always flew away, and I came to the conclusion that I had not succeeded in getting any salt or, at any rate, not enough on to the tail of any one of them.

Then I devised a great experiment. There was a sort of creek eight feet long and three feet broad at the west end of the ornamental water in St. James’s Park. My sister attracted several ducks with offerings of bread into this creek, and I, standing near its entrance, with a huge paper bag of salt, trembled with excitement at the approaching success of my scheme. I poured quantities—whole ounces of salt—on to the tails of the doomed birds as they passed me on their way back from the creek to the open water. Their tails were covered with salt. But, to my surprise and horror, they did not stop! They gaily swam forward, shaking their feathers and uttering derisive “quacks.” I was profoundly troubled and distressed. I had clearly proved one thing, namely, that my nursemaid, uncle, and several other trusted friends—but not, I am still glad to remember, my father—were either deliberate deceivers or themselves the victims of illusion. I was confirmed in my youthful wish to try whether things are as people say they are or not. Somewhat early perhaps, I adopted the motto of the Royal Society, “Nullius in verba.” And a very good motto it is, too, in spite of the worthy Todhunter and other toiling pedagogues, who have declared that it is outrageous to encourage a youth to seek demonstration rather than accept the statement of his teacher, especially if the latter be a clergyman. My experiment was on closely similar lines to that made by the Royal Society on July 24, 1660—in regard to the alleged property of powdered rhinoceros horn—which was reputed to paralyse poisonous creatures such as snakes, scorpions, and spiders. We read in the journal-book, still preserved by the society, under this date: “A circle was made with powder of unicorne’s horn, and a spider set in the middle of it, but it immediately ran out several times repeated. The spider once made some stay upon the powder.”