After having demonstrated the presence of carbon in sulphur, I have to demonstrate the presence of hydrogen and oxygen which, according to analogy, ought to be found in it.
Two months pass in calculations and surmises till the apparatus necessary for making the experiments is exhausted. A friend advises me to go to the Sorbonne laboratory, where strangers are admitted. But my timidity and shyness of crowds does not permit me to think of it; I suspend my experiments and take a rest.
One fine spring morning I wake up in good spirits. I walk through the Rue de la grande Chaumière to the Rue de Fleurs, which leads to the Jardin du Luxembourg. The small, pretty street is quiet, the great avenue of chestnut trees is cheerful and green, broad and straight as a racecourse. Quite in the background the statue of David rises like a boundary mark, and high over all the dome of the Pantheon, surmounted by a golden cross, seems to touch the clouds. I remain standing, delighted with the significant spectacle, when accidentally on my right my eyes fall on a dyer's shield at the end of the Rue de Fleurs. Painted on the window of the dyeing-house stand over a silver cloud the initials of my name A.S., and over them is arched a rainbow.
_Omen accipio!_ and am reminded of the passage in Genesis, "I have set my bow in the clouds to be a sign of the covenant between me and the earth."
I seem no longer to touch the ground, but to float in air, and with winged feet enter the garden, which is now quite empty. In this early morning hour I am the exclusive possessor of this park, with all its glory of roses, and I know all my flowers in their beds--chrysanthemums, verbenas, and begonias.
Going down the racecourse I reach the boundary mark, pass through the trellised gate to the Rue Soufflot, and turn to the Boulevard St. Michel, where Blanchard's antiquarian book-shop attracts my attention. Casually I take up an old chemical work by Orfila, open it at haphazard and read, "Sulphur has been classified among the simple bodies. Davy and Berthollet, however, have endeavoured to prove by their able experiments that it contains hydrogen, oxygen, and a third basal element which has not yet been distinguished."