442 



SCIENCE. 



[N. S. Vol. XX. No. 509. 



amount was only about one per cent, of the 

 total helium in the mineral. In one instance 

 0.7 per cent, of the gas obtained was hydrogen, 

 which Moss thinks may have been the product 

 of the action of radium upon the water pres- 

 ent. The conclusion drawn is that the helium 

 exists in pitchblende in a free state, enclosed 

 in exceedingly small cavities. 



HELIUM IN MINERALS FROM GREENLAND. 



An investigation has been made by Julius 

 Thomsen of the gases contained in a fluorspar 

 from Greenland, containing fluorids of the 

 rare earths. At a red heat a kilo of the spar 

 gave off about 800 cubic centimeters of gas, 

 715 of which were carbon dioxid, probably 

 due to the presence of ferrous carbonate. The 

 other 85 cubic centimeters consisted of hydro- 

 gen, carbon monosid, hydrocarbons and 24r-27 

 cubic centimeters of helium. When the 

 mineral was treated, prior to heating, with 

 hydrochloric or nitric acid, or both, while the 

 carbon dioxid was reduced to about 40 cubic 

 centimeters, the amount of helium remained 

 unchanged. The same was true even after 

 treatment with concentrated sulfuric acid, or 

 fusion with caustic potash. From these ex- 

 periments Thomsen concludes that if the 

 helium is not free, it must be present in an 

 extraordinarily firm compound. Other min- 

 erals from Greenland containing rare earths 

 were also examined, including steenstrupite, 

 eudialyte and a silicate from Ivigtut, and 

 while much gas was often evolved, no trace of 

 helium was found. The same was true of a 

 green fluorspar from England, which gave on 

 heating a blue fluorescence. 



CONDUCTniTY OP RADIUM SOLUTIONS. 



It would not be surprising, in view of the 

 ionizing power and high atomic weight of 

 radium, if its salts showed an abnormal con- 

 diictivity in solution, but recent experiments 

 of Kohlrausch and Henning indicate that 

 this is not the case. Assuming the atomic 

 weight of radium as 225 and working with 

 about 8 milligi'ams of the bromid, they find 

 the molecular condtictivity and the migration 

 velocity of the radium ion to be very close to 

 that of barium, and not far from that of 



strontium and calcium. If the atomic weight 

 of radium be 258, as claimed by Eunge and 

 Preeht, these values become only a little higher. 

 They consider this as a new example of the 

 small part played by the atomic weight in de- 

 termining the characteristics of a salt. 



METALS IN MINERAL WATERS. 



Much has been written on the therapeutic 

 action of the heavy metals in mineral waters, 

 and a new suggestion has been put forward 

 by Garrigou in the Oomptes Bendus. After 

 submitting the water of the old Eaux-Bonnes 

 spring to prolonged dialysis, he finds the larger- 

 part of the heavy metals in the undialyzable 

 portion ; that is, they are present in a colloidal 

 form, doubtless in organic combination. He 

 considers that these metallic compounds are 

 of the nature of oxydases and play an impor- 

 tant part in the therapeutics of mineral water. 

 This discovery would seem also to be of im- 

 portance in water analysis, since these metals 

 would not react with the ordinary reagents 

 for metals in solutions, and complete destruc- 

 tion of all organic matter in the water would 

 thus be an indispensable preliminary step be- 

 fore the determination of at least any heavy 

 metals. 



ACTION OF METALS ON FERMENTATON. 



An interesting series of experiments by 

 Leopold Nathan are described in the Ceniral- 

 hlatt fur BaMeriologie und Parisitenkunde, 

 made in the effort to determine how far metals 

 and metal containers have an inhibitory ac- 

 tion upon fermentation processes. The ex- 

 periments were carried out by immersing pure 

 metals in the form of thin cylinders in the 

 fermenting liquid. Both cider and beer were 

 used. In the case of cider, in general more 

 of the metal passed into solution, but the 

 ferment was more resistant. The liquid re- 

 mained clear during and after the fermenta- 

 tion. Beer was much more sensitive. With 

 the iron cylinder, a grayish sheen was visible 

 in the liquid, which during the fermentation 

 became inky, and finally a black precipitate 

 appeared. German silver, copper, zinc, brass 

 and bronze had a decidedly strong inhibitory 

 action upon the fermentation, while tin and 



