654 POPULAR SCIENCE MONTHLY. 



Against such assumption we must protest. I have nothing 

 against the doctrines save that they are not yet true. In them- 

 selves, as I have said, they are attractive. One may naturally 

 feel a hopeful interest in wide-reaching theories which seem pos- 

 sible, but are still unproved or unworkable. This is, however, not 

 "belief." It is rather open-mindedness, open to negative evidence 

 as well as to the positive. 



As science goes wherever the facts lead, so science must stop 

 where the facts stop. It can not add to its methods the running 

 high jump, nor place the divining rod with the microscope, cru- 

 cible, and calculus among its instruments of precision. Beyond 

 the range of scientific knowledge extend the working and the 

 unworkable hypotheses. Beyond the confines of these extends the 

 universe of the mind, the boundless realm which is the abode of 

 philosophy. None should better realize those distinctions than 

 men of science. 



[7'o be continued.] 



A YEAR OF THE X RAYS. 



By D. W. HEKING, 

 peoressob of physics, new york university. 



THE incredulity which greeted the first reports of Prof. Ront- 

 gen's famous discovery gave place, upon their confirmation, 

 to a delirium of enthusiasm, experimentation, and expectation. 

 So startling and so novel were the facts reported by the discov- 

 erer that no prediction seemed too wild, no penetration into the 

 unknown either impossible or improbable. The condition of 

 mind actually prevailing at that time with a large number of 

 persons is admirably shown by President Jordan's amusing arti- 

 cle on the Sympsychograph in the Popular Science Monthly for 

 September, 1896. 



Prof. Rontgen reported his investigations in a paper before 

 the Physico-Medical Society of Wurzburg, in December, 1895. 

 The account of his paper was transmitted to America in a few 

 brief statements, January 7, 189G, the full report not arriving 

 until some weeks later. Popular interest was focused upon the 

 fact that the X rays, as its discoverer provisionally named the 

 mysterious agency, would reveal a bony skeleton within its case 

 of fleshy tissue, and the famous picture of a hand in which the 

 bones thus stood revealed was soon to be found in every city of 

 Europe and America. The realism of this weird picture simply 

 fascinated all who beheld it. Attempts were made to repeat and 

 extend the original experiments wherever there was any sem- 

 blance of apparatus suited to the purpose. An electric poten- 



