2o8 



THE ALUMNI JOURNAL. 



HELIU/1. 



Professor Ramsay, at a recent meeting 

 of the Chemical Society, read what many 

 in the audience regarded as his first offi- 

 cial paper on Helium, although he an- 

 nounced his discovery at the anniversary 

 meeting. We are indebted to the Chem- 

 ist and Druggist for the following inter- 

 esting abstract of the paper : 



Professor Ramsay first assigned a share 

 of the credit to Dr. Norman Collie, who 

 had, with Mr. Travers, been aiding him 

 in his work. About forty different min- 

 erals, more or less rare, had been exam- 

 ined with the view of finding helium in 

 them. It had been found in about fifteen 

 of them. The chief sources up to the 

 present were clevite, broggerite, samars- 

 kite, English pitchblende and monazite. 

 He had specimens in vacuum tubes from 

 all these sources, and handed round a 

 dozen small direct-vision spectroscopes 

 for the Fellows to examine the spectrum. 

 The light was now turned down, and the 

 giant Ruhmkorf began to speak. The 

 helium spectrum flashed out to magnifi- 

 cent advantage, and those who did not 

 know would have felt certain that the 

 huge yellow band now called D 3 was the 

 double sodium line, so great was the in- 

 tensity. The methods used in obtaining 

 the gas were the following : (i) Pump- 

 ing out the gas evolved on heating the 

 mineral in an evacuated piece of com- 

 bustion tube (this often contained hydro- 

 gen and carbonic acid, with sometimes a 

 hydrocarbon, but never any argon) ; (2) 

 Powdering the mineral finely with 

 KHSO4 and heat ; (3) Or boiling with 

 H 2 S0 4 (70 per cent.) preferably in a 

 current of C0 2 * The gas is purified by 

 absorbing with KOH, mixing with oxy- 

 gen, exploding over a little KOH and 

 mercury, and it can then be passed over 

 ignited magnesium and copper oxide 

 when necessary. The spectra showed 

 five specially brilliant lines — one in the 



red, then the famous yellow line, one in 

 the green, one in the blue, and finally 

 one in the violet. From pitchblende 

 Professor Ramsay only obtained about ^ 

 cc. from 70 grains of material. It " didn't 

 pay to extract," said Professor Ramsay, 

 amidst much laughter. Broggerite, a 

 mineral which resembles cleveite, merely 

 having the small quantity of yttrium 

 therein contained replaced by thorium, 

 is a useful source of the gas. In justic e 

 to Hillebrand he said that uraninite does 

 give off large quantities of nitrogen, 

 and he had received a letter from this 

 chemist saying he had observed numer- 

 ous strange and new lines in the spec- 

 trum, but had not been bold enough 

 to assume he had discovered a new ele- 

 ment. The remainder of the work was 

 devoted to a study of the properties of 

 the gas. He had taken the density of 

 three samples obtained from the follow- 

 ing sources : (1) Cleveite, (2) Brogger- 

 ite, (3) Samarskite. The gases were in 

 all cases finally passed over ignited mag- 

 nesium, copper oxide and phospharic an- 

 hydride. All three gave a density of 

 2.2. L,est a misunderstanding might 

 arise, he pointed out that he gave his 

 original figure, 39, as the maximum 

 density, not as the true density. The 

 exact figure of the three samples was 

 2218, and on further being heated over 

 ignited magnesium he had reduced this 

 to 2133. He had only about 30 cc. to 

 use for the determination, but this ad- 

 mitted of a reading with an error of less 

 than 2 per cent. The wave-length of 

 sound was also determined by the lyco- 

 podium method, and the result of the 

 ration of specific heats at constant vol- 

 ume and constant pressure was found to 

 be 1.652. For a monatomic gas this 

 should be, theoretically, 1.66. So that 

 the monatomicity was apparently estab- 

 lished. Helium is the least soluble of 

 all the gases, 100 volumes of water dis- 



