October 5, 1900.] 



SCIENCE. 



531 



metal, galvanic currents are generated which 

 rapidly corrode the aluminum. It has hence 

 been impossible to use vessels where the metal 

 was soldered. A process has recently been de- 

 vised which enables the weldiug of aluminum 

 without the aid of a flux. This will greatly 

 increase the usefulness of aluminum. The ten- 

 sile strength of the metal is only one-fourth 

 less than that of copper, and while its conduc- 

 tivity for heat is only half as great as that of 

 copper, it is twice as great as that of iron. 

 The use of aluminum as a conductor of elec- 

 tricity is also growing rapidly. 



An interesting investigation has recently been 

 carried out by H. J. Moller of Copenhagen, and 

 published in the Berichte of the German Phar- 

 maceutical Society, on colored glasses, with 

 particular reference to the proper color for 

 bottles which are intended to protect medi- 

 cines, etc., from the chemical action of the 

 light. It was found that the best protection is 

 afforded by black (opaque), red, orange and 

 dark yellowish- brown glass — -light brownish- 

 yellow, dark green (with no bluish tint) and 

 dark brownish-green glasses afford quite good 

 protection ; bluish-green, violet, milky, bluish 

 and colorless glasses give little if any protection 

 from the actinic rays of sunlight. For the 

 preservation of wine, beer and liquors, dark 

 brownish-yellow and dark yellowish-brown 

 bottles are to be preferred, while light brown, 

 light green and bluish-green glass is less to be 

 recommended. 



A NEW and curious chapter has been added 

 to the chemistry of the radio-active elements 

 by A. Debierne in one of the latest Comptes 

 Sendus. By dissolving barium chlorid in a 

 solution of actinium and then crystallizing or 

 precipitating it out, a radio-active barium is 

 obtained which shows many similarities to 

 the radiferous barium from pitch blende. Its 

 rays are capable of ionizing gases, excite the 

 phosphorescence of barium cyanoplatinite, are 

 photographically active, and are partially de- 

 flected in a magnetic field. The anhydrous 

 chlorid thus obtained is self-luminous. On 

 the other hand, this salt shows only the spec- 

 trum of pure barium, while that from pitch 

 blende gives the radium spectrum. The 



former gradually decreases in activity, while 

 the latter increases up to a maximum, at which 

 it remains constant. Debierne considers that it 

 is improbable that his active barium should 

 contain any radium or any actinium, but 

 that it is probable that by prolonged contact 

 with actinium salts the barium has become it- 

 self temporarily active. This inductively ac- 

 tive barium appears to be intermediate in its 

 properties between vadium and barium. 



J. L. H. 



EXPERIMENTAL STATIONS IN HAWAII AND 

 POBTO BICO* 



The last appropriation acts for the Depart- 

 ment of Agriculture carried provisions for the 

 inauguration of experiment stations in the 

 islands of Hawaii and Porto Eico. In accord- 

 ance with this the preliminary steps have been 

 taken to determine the best plan of operation 

 in each case and the subjects which are in most 

 need of immediate attention. 



Professor S. A. Knapp, of Louisiana, who for a 

 considerable number of years has been engaged 

 in subtropical agriculture on an extensive scale, 

 was selected to investigate the agricultural con- 

 ditions and possibilities of Porto Eico. Pro- 

 fessor Knapp went to the island early in June. 

 In general he will study the present agricultural 

 conditions existing in Porto Eico, the lines of 

 experimental investigation which should be 

 undertaken there, especially in the immediate 

 future, and the locations suitable for stations, 

 together with the approximate expense of in- 

 augurating and maintaining the work of the 

 stations. He will also look into the feasibility of 

 undertaking cooperative experiments with the 

 residents of Porto Eico, and the best means of 

 reaching the people through difierent classes of 

 publications, demonstration experiments, and 

 otherwise. 



For the preliminary survey of the conditions 

 in the Hawaiian Islands, Dr. W. C. Stubbs, di- 

 rector of the Louisiana Experiment Station, 

 has been selected as especially fitted by experi- 

 ence. Dr. Stubbs sailed for Hawaii about the 

 middle of July, and will spend the month of 

 August in the islands. The conditions there 

 with reference to station work are different 



* From the Experiment Station Record. 



