February 5, 1904.] 



SCIENCE. 



Til 



Johanngeorgenstadt, Saxony, and Central City, 

 Colorado, caused the diamond to phosphoresce. 

 It was further shown that if either kunzite (a 

 variety of spodumene), pectolite or woUaston- 

 ite, pulverized, were mixed with radium- 

 barium carbonate, of 240 activity, the mixed 

 powder became permanently luminous. When 

 these mixtures were put in a Bologna flask and 

 held on a metal plate, hot but not showing any 

 color, they immediately became very luminous 

 and remained so for a long time. Kunzite, 

 pectolite and wollastonite became phosphores- 

 cent by heating alone, the kunzite showing an 

 orange glow. When a kunzite crystal 5 cm. 

 square and 5 cm. thick was exposed to the pas- 

 sage of an oscillating current, the entire crys- 

 tal glowed an orange pink, losing its lilac 

 color, a well-defined line through the center in 

 the path of the current being much more bril- 

 liant; this phosphorescence lasted for quite a 

 time after exposure. Further experiments 

 were made with the same sensitive diamond 

 mentioned above as to its tribo-luminescence. 

 Prints were obtained from negatives made by 

 laying the diamond face downward directly 

 upon the photographic plate, and rubbing the 

 back of the diamond with a stick coated with 

 wool, in one instance for a quarter of a minute, 

 in another for one half minute, the tribo- 

 luminescence induced causing the printing. 

 The same type of diamond from British 

 Guiana, when heated on a metal plate below 

 redness, phosphoresced distinctly, as also did 

 pectolite and wollastonite. We have here, 

 therefore, luminescence of the tiffanyite body 

 in diamond, produced by radio-active pitch- 

 blende, by friction and by heat. 



The next paper on the program was the first 

 of a series of papers on ' Eecent Progress in 

 Physical Science,' and was delivered by Dr. 

 Bergen Davis, who spoke on ' The Latest 

 Theories Relating to the Discharge of Elec- 

 tricity in High Vacua, and Ionization of 

 Gases.' Account was given of Dr. H. A. 

 Wilson's investigation of the distribution of 

 electrical intensity along the striated positive 

 column, and his theory for the electrical in- 

 tensity in a uniform positive column. An out- 

 line was also given of Professor J. J. Thomp- 

 son's theory of the discharge through Geissler 



tubes. Dr. Davis also reviewed Professor J. 

 S. Townsend's theory of the sparking potential. 

 Professor Townsend having showed that the 

 ionization is due to impact of both positive 

 and negative ions with the neutral molecule. 

 The theoretical sparking potential thus de- 

 duced agrees very closely with the experi- 

 mental value. 



Charles C. Trowbridge, 



Secretary. 



THE AMERICAN CHEMICAL SOCIETY. 

 NEW YORK SECTION. 



At the meeting held on January 8 at the 

 Chemists' Club, 108 West 55th Street, the pro- 

 gram was as follows : 



T/te Dietetic Value of Patent Foods: W. D. 



Halliborton. 



Professor Halliburton, who was present- as 

 the guest of the section, spoke especially of 

 the conditions influencing the digestibility of 

 various foods and dietetic preparations, the 

 relative importance of nitrogenous and non- 

 nitrogenous nutrients, the disadvantages of 

 separating a single nutrient from the other 

 constituents of the food in which it occurs, 

 and the question of the nutritive values of 

 meat extracts and proteolytic products. It 

 was pointed out that while the meat extracts 

 are practically devoid of food value, the prep- 

 arations which consist of proteolytic products, 

 such as proteoses and peptones, have practi- 

 cally the same nutritive effect, ' nitrogen for 

 nitrogen,' as the original proteids, being syn- 

 thesized to proteids in the body, probably in 

 the epithelial cells. In conclusion Professor 

 Halliburton urged the cooperation of chemists 

 with physiologists and physicians in the edu- 

 cation of the public, and the prevention of 

 fraud in the matter of artificially prepared and 

 ' patent ' foods. 



Notes on the Preparation of Standard 

 Alkalimetric Solutions: F. D. Dodge. 

 Dr. Dodge reviewed the principal methods 

 employed and discussed especially the merits 

 of various acid and alkaline substances which 

 have been suggested as standards for use in 

 the direct methods of standardizing. For this 

 purpose he proposes the use of salicylic acid 



