Bacteria in Daily Life

fore the world of microorganisms had been discovered, but curiously has found an echo in the writings of a distinguished bacteriological chemist in recent years. " Laissons donc entrer largement partout l'air et le soleil," writes M. Duclaux; " c'est la une maxime bien ancienne, mais si les mots sont vieux I'ide'e qu'ils revetent est nouvelle." The interpretation of this ancient maxim is indeed very modern, and we must turn to the investigations made within the past few years to learn with what justification M. Duclaux thus expresses himself, for it is only comparatively recently that we have learnt the novel fact that sunshine, whilst essential to green plant life, is by no means indispensable to the most F 65 primitive forms of vegetable existence with which we are acquainted, i.e. bacteria. In fact, we have found out that if we wish to keep our microbial nursery in a healthy, flourishing condition, we must carefully banish all sources of light from our cultivations, and that a dark cupboard is one of the essential requisites of a bacteriological laboratory. That light had a deleterious effect upon microorganisms was first discovered in this country by Messrs. Downes and Blunt, and their investigations led Professor Tyndall to carry out some experiments on the Alps, in which he showed that flasks containing nutritive solutions and infected with bacteria when exposed in the sunshine for twenty- four hours remained unaltered, whilst similar vessels kept in the sha...