Note 33 — THE MODES OF ORIGIN OF LOWEST ORGANISMS.
Reading edition
It was necessary to boil the solution first, in order to destroy any living things or dead ferments which it might contain. It must contain one or the other, because an unboiled solution of this kind, in a corked bottle about half full, will always become turbid; whilst, after it has been boiled, it may be kept indefinitely under similar conditions without becoming turbid.