1895.] Helium, a Gaseous Constituent of certain Minerals. 81 



I. " Helium, a Gaseous Constituent of certain Minerals. 

 Part I." By WILLIAM RAMSAY, F.R.S., Professor of 

 Chemistry in University College, London. Received 

 April 27. 



1. Introductory. 



IN seeking for a clue which would guide to the formation of com- 

 pounds of argon, Mr. Miers, of the British Museum, kindly informed 

 me that a gas, supposed to be nitrogen, was obtainable from certain 

 minerals containing the metal uranium, and notably from cleveite, a 

 Norwegian mineral discovered by Nordenskjold. The gas evolved 

 from a number of such minerals had been examined by Dr. W. P. 

 Hillebrand, of the United States Geological Survey, and was pro- 

 nounced by him to be nitrogen. The gas, which is evolved from some 

 uraninites by the action of weak sulphuric acid, or by fusion with 

 sodium carbonate, gave, in the hands of Dr. Hillebrand and Dr. 

 Hallock,* the usual fluted nitrogen spectrum, and on sparking with 

 hydrogen in presence of acid, or with oxygen in presence of alkali, 

 contraction ensued. From the first of these experiments they were 

 able to prepare a weighable quantity of ammonium platinichloride. 



In a private letter from Dr. Hillebrand, from which he allows me 

 to quote, he states : 



" The circumstances and conditions under which my work in this 

 line was done were unfavourable ; the chemical investigations had 

 consumed a vast amount of time, and I felt strong scruples about 

 taking more from regular routine work. I was a novice at spectro- 

 scopic work of this kind, and was thereby led to attach too little 

 importance to certain observations which in the light of your dis- 

 coveries deserved the utmost consideration. Among other things, it 

 puzzled me that the formation of ammonia should have proceeded so 

 slowly, and that only a comparatively small amount of the gas should 

 have been converted at the expiration of even several days' passage 

 of the current. But, having had no previous experience, I was unable 

 to judge whether this was especially abnormal or not ; it might have 

 been due to insufficient current, or to some other cause. A similar 

 observation applies to the sparking with oxygen, which was only 

 carried far enough to prove a contraction, and to obtain the tests for 

 nitric acid. 



" It doubtless has appeared incomprehensible to you, in view of the 

 bright argon and other lines noticed by you in the gas from cleveite, 



* " On the Occurrence of Nitrogen in Uraninite, Ac.," by W. F. Hillebrand, 

 Bull. No. 78, U. S. Geological Survey, 1889-90. 



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