Science Evidence Research Articles

Positive Evidence in Science and Technology

If the problem of induction were soluble, it should be solved inductively: by observing how scientists observe, etc. The fact is that scientific research is successful, and the real question is, will it be so in future? If there is a formula of induction by which success is achieved, then by this formula we can say, as long as it will be used science will succeed. If there is no formula it looks as if future success in scientific research is most doubtful. Hence, a transcendental argument for induction goes, there is an inductive formula. Since, however, such a view of induction is rejected even by inductivists as naive, the argument collapses. Hence the question is, on what basis do we project the future success of science? My answer is that this future success is built into our social institutions and is partially institutionally safeguarded.

Evidence for a Science of Recreational Guidance

Evidence for a Science of Recreational Guidance

The Romance of the Nitrogen Atom

THE letter of Dr. F. J. Allen (NATURE, May 4) on the critical temperature of living substances has interested me immensely. The ideas contained in it have often presented themselves to me in a crude way, and I hope Mr. Allen will find opportunity for elaborating them. I have often thought, when pondering over what one may venture to call the versatility of nitrogen, that a useful book might be written on the chemistry of the nitrogen compounds, including the mineral and organic compounds of that element in one view. If it did no other service it would help to save the mind of the chemical student from being enslaved by the phrase, “the chemistry of the carbon compounds.” If the phrase “Ohne Phosphor kein Gedanke” is true, may we not with equal truth say “Ohne Stickstoff kein Leben”? The marvellous powers stored in the carbon atom are sufficiently en evidence in chemical science; yet may we not recognise the nitrogen atom as the magic “demon” (borrowing a figurative term from Clerk Maxwell) that holds the wand, that (under given conditions such as are noted by Dr. Allen) turns the atoms of oxygen and hydrogen hither and thither in the multiplex atomic relations of growth and metabolism in the living organism, and especially in that little understood complex we call chlorophyll? We know that the inert N2 molecule of the atmosphere is made up of atoms which, in the nascent state, are possessed of great chemical energy, and we may fairly, I think, explain the inertness of ordinary atmospheric nitrogen by the stability of its molecule (N2) as arising out of a difference in the ionic constitution of the two atoms which form the molecule. Is it not here that we may seek for the explanation of the otherwise puzzling fact that in the extremely stable compound NH3 the nitrogen atom is trivalent, while in the oxides, halides, &c., it is pentavalent? The action of the nitrogen atom, in the way suggested by Dr. Allen, is illustrated by the well known necessity in the fertilisation of soils for the conversion of NH3 into nitrates of alkaline bases, in order that the nitrogen in a more unstable state of combination may do its special work in the internal economy of the plant. I recollect discussing this matter some years ago with Dr. Voelcker, when I had the pleasure of meeting him at an agricultural gathering in this neighbourhood. The modern idea of ionisation of atoms seems also to throw light upon the fact that N2 and H2 combine to form NH3 under the influence of the silent electric discharge, while at the temperature of the spark-discharge NH3 is again split up into N2 and H2. The running down also of HNO3 through the whole series of oxides into ammonia in the Grove cell is full of interest from this point of view, and the subject, with its manifold ramifications, is a fascinating theme for a thesis.