1898.] MICROSCOPICAL JOURNAL. 201 



two-thirds inch objective of a second microscope contain- 

 ing a one inch ocular, he will find, if his microscopes are 

 in alignment, and if the foci are correctly adjusted, a 

 better and larger ima*e than can possibly be produced 

 by a sixteenth inch objective. In fact, a magnification 

 equal to the best twenty-four inch objective, and a field 

 from ten to fifty times as large, and a depth from five to 

 twenty times as great. It is useless for microscopists to 

 deny this because I have the evidence in my laboratory. 

 It is not a matter of discussion. 



Can any one suppose that I would make these state- 

 ments at random without having tried the experiments ? 

 And is it true that microscopists are willing to make 

 criticisms without first having tried the experiments ? 

 It may not be known to some microscopists that recent 

 progress in physics has been enormous, especially in the 

 field of ether-dynamics. This progress makes it possi- 

 ble for me to predict that the very best microscopy will 

 soon consist in using the invisible rays above the violet 

 and of the spectrum for best results. I expect to see 

 within a year a photograph made of the inner tissues of 

 the body of a living person by means of photo-micro- 

 graphy, and ordinary photography with invisible rays. 

 I do not mean a skiagraph, such as are produced by the 

 X-rays, but a photograph of the details of the surface 

 of organs and of their inner structure. I have provided 

 myself with a heliostat, made for me by the 8ociete de ^ 

 Genevoise. The mirror is 12 inches in diameter and it 

 will throw a ray of sunlight into my microscope with 

 considerable precision. This beam will be condensed 

 into abeam at least one hundred times less in diameter 

 and then rendered parallel and then thrown through the 

 microscope either before or after having been rendered 

 monochromatic by means of suitable prisms. A micro- 

 scope made especially for mono-chromatic light will re- 

 place those of usual form. I am experimenting to get 



