Report on the Quantum Theory of Spectra #251613

The present report was written originally for the private use of Messrs. Adam Hilger, and was then, at their instance, amplified and prepared for publication. But even with this extension it will be found to contain a brief account of only the most important contributions to the Quantum Theory of Spectra, a new field'6f inquiry opened only six or seven years ago by Niels Bohr, but already very vast and rapidly growing and ramifying in multiple directions. It will, no doubt, soon call for a supplement. As it is, however, it is hoped to be a helpful guide for those desiring to enter upon this new and strangely fascinating line of thought and investigation.