“Be sure and remember, kiddies, what you have just seen; and, if ever any one talks to you about showers of blood, don’t be silly and frightened. A pretty Butterfly is the cause of those blood-red stains, which have been known to terrify country-folk. The moment she is born, she casts out, in the form of a red liquid, the remains of her old caterpillar body, a body remodelled and reborn in a beautiful shape. That is the whole secret.” When my artless visitors have departed, I resume my examination of the rain of blood falling under the cover. Still clinging to the shell of its chrysalis, each Tortoiseshell ejects and sheds upon the paper a great red drop, which, if left standing, deposits a powdery pink sediment, composed of urates. The liquid is now a deep crimson. When the whole thing is perfectly dry, I cut out of the spotted paper some of the richer stains and steep the bits in ether. The spots on the paper remain as red as at the outset; and the liquid assumes a light lemon tint. When reduced by evaporation to a few drops, this liquid provides me with what I require to soak my square of blotting-paper. What shall I say to avoid repeating myself? The effects of the new caustic are precisely the same as those which I experienced when I used the droppings of the Processionary. The same itching, the same burning, the same swelling with the flesh throbbing and inflamed, the same serous exudation, the same peeling of the skin, the same persistent redness, which lingers for three or four months, long after the ulceration itself has disappeared. Without being very painful, the sore is so irksome and above all looks so ugly that I swear never to let myself in for it again. Henceforth, without waiting for the thing to eat into my flesh, I shall remove the caterpillar plaster as soon as I feel a conclusive itching. In the course of these painful experiences, friends upbraid me with not having recourse to the assistance of some animal, such as the Guinea-pig, that stock victim of the physiologists. I take no note of their reproaches. The animal is a stoic. It says nothing of its sufferings. If, the torture being a little too intense, it complains, I am in no position to interpret its cries exactly or to attribute them to a definite impression. The Guinea-pig will not say: “It smarts, it itches, it burns.” He will simply say: “That hurts.” As I want to know the details of the sensations experienced, the best thing is to resort to my own skin, the only witness on whose evidence I can rely implicitly.