JAMA 100 Years Ago Section Editor: Jennifer Reiling, Assistant Editor.
A number of years ago Lord Kelvin offered what was then considered by many the extravagant hypothesis that life first came to this planet on meteorites thrown off from other celestial bodies and carrying the germs of their existing organisms. The theory was widely discussed for a time, but had its little day and was apparently dropped as a mere hypothesis probably incapable of proof and open to too many objections to require serious consideration. It is not dead, however, and it has again been brought before the public in a modified form by the distinguished Swedish physico-chemist, Arrhenius, who figures out the possibility of germs, even from other solar systems, reaching us, propelled by light and with their vitality maintained by the preservative action of the low temperature of space. It is somewhat significant perhaps that one to whom the more advanced chemistry of the day owes so much, should consider it worth while to assume an extra mundane origin of life, when so many of the minor chemico-biologists are proclaiming that life is itself a form of chemism. If the universe is permeated with wandering germs and all life and evolution are everywhere essentially the same, we are then liable to almost anything in the way of pathologic possibilities. The chance arrival on our planet of some ultra virulent germ might at any time produce a catastrophy [sic] as fatal to the human race as the collision of a dark star with our sun so vividly imagined by Professor Newcomb. Such speculations are perhaps of no practical use, but after all the question of the origin of life is an ever recurring one. Any one who, in the present state of our knowledge, assumes that it is settled—that any hypothesis can be considered as definitely proved—must have very inadequate ideas of what constitutes proof.
THE ORIGIN OF LIFE.. JAMA. 2007;298(6):691. doi:10.1001/jama.298.6.691-b