208 IHE N RAYS OF M. BLONDLOT. 



The experi'^ients on polarization suggested to M. Blondlot the pos- 

 sibility that the new rays might also be refracted. He tested this by 

 interposing a quartz prism, and found that in fact the ra^^s were now 

 diverted from a straight line, so that he was obliged to carry the 

 sparking device to one side in oi-der to reach a point of increased 

 luminosity. By means of a quartz lens the fact of the refraction of 

 the rays was further verified, and following this it was found that the 

 rays could be reflected regularly and dilfustdy, just as is the case with 

 ordinary light. As polarization, refraction, and reflection are not 

 qualities of X-rays, but are essentialh' qualities of ordinary light, M. 

 Blondlot drew the conclusion that he was now dealing with radiation 

 propagated by waves in the ether in essentially the same manner as 

 ordinary light. This new type of rays he found to be transmitted by 

 wood, paper, aluminum, and many other metals, but to produce no 

 direct efl'ect upon the eye, the photographic plate, or a phosphorescent 

 screen, and he w^as at flrst unable to recognize them excepting b}^ 

 means of the little sparking device. 



The experiments with refraction in prisms and lenses had indicated 

 that the index of refraction of these rays in quartz was very high and 

 indeed exceeding 2. Professor Kubens had not long before discov- 

 ered mys of great wav€ length for which the index of refraction in 

 quartz was about 2.18. This similarity of refractive index led M. 

 Blondlot at first to think that perhaps he was now dealing with a type 

 of radiation belonging to the extreme infra-red, and as Rubens had 

 employed a Welsbach lamp as a source of the radiations he had meas- 

 ured, M. Blondlot sought to determine if these new ravs were also 

 emitted by this source. Shielding the lamp which he employed by an 

 iron covering having a small aluminum window, he was aide to detect 

 the presence of the ra^'s in question in its radiation by the aid of the 

 small sparking device. When the quartz lens was used to form an 

 image of the source, the rays appeared not to be homogeneous, but to 

 contain at least four dift'erent varieties whose indices of refraction 

 were, respectively, 2.94, 2.02', 2. 44, and 2.29. With the exception of 

 lead, rock salt, platinum, and water, the rays were found to be trans- 

 missible by moderate thicknesses of many ditterent substances, includ- 

 ing tin foil, copper, aluminum, steel, silver, gold, paraflan, black 

 rubber, and others. 



sou HOES OF THE KAYS" AND METHODS EMPLOYED IN THEIR EECOCiNITION. 



M. Blondlot now gave a jiame to these rays, calling them N rays, 

 after the city of Nancy, in which he lives. He claims to detect their 

 presence in the emission of luminous gas flames, as well as in the 

 sources already mentioned, ])ut he failed to find them in the emission 

 of a l^unsen burner. The Nernst lamp is spoken of as a speciall}^ 

 intense source of them. 



