92 Scientific Intelligence. 



and purification, but the conclusion is reached that these residues 

 may become a practical source of the rare metal. — C. i?., cliii, 

 1278. h. l. w. 



3. The Acid Salts of Dibasic Acids. — It is customary to 

 assume that bivalent acids form acid salts readily on account of 

 the presence of two hydrogens in the acid molecule, and this 

 idea is expressed in the formulas usually given to these acid salts. 

 For instance, the acid potassium sulphate and oxalate are indi- 

 cated by the formulas HKS0 4 and HKC 2 4 . E. Jungfleisch 

 and P. Landrietj have shown, however, that acid camphorates 

 are not compounds of this type but are formed by the union of 

 the free acid with the neutral salt. They have also carefully 

 investigated the acid potassium oxalate, and find that it does not 

 crystallize unchanged from its solutions. They conclude, there- 

 fore, that the formula of this salt should be written K 2 C 2 4 .H 2 C 2 4 , 

 instead of in the usual manner previously mentioned. This con- 

 clusion of these investigators is perhaps not entirely free from 

 criticism, but it is strengthened by the known existence of acid 

 nitrates and acid salts of other univalent acids. — C. R., clviii, 

 1306. h. l. w. 



4. Fluorsulphonic Acid. — Otto Ruff and H. J. Braun - have 

 found that this acid, which has the formula S0 3 HF, may be con- 

 veniently prepared by distilling a mixture of fluorspar with fum- 

 ing sulphuric acid. The best yield is obtained when the fuming 

 acid contains about 60 per cent of the free anhydride, SO,. The 

 operation can be carried out in a simple retort made of wrought 

 iron pipes, but in order to make it perfectly pure it must be redis- 

 tilled in platinum. The pure acid boils at 162*6° C. at atmos- 

 pheric pressure. With solid sodium chloride or fluoride, it forms 

 sodium fluorsulphonate with violent evolution of hydrochloric or 

 hydrofluoric acid. It is remarkably stable towards heat and does 

 not decompose, apparently, even at 900° C. However, reducing 

 agents act upon it when heated, forming HF and S0 2 . Finely 

 divided sulphur is acted upon by it at its boiling temperature 

 with the formation of the compounds just mentioned. — Berichte, 

 xlvii, 646, 656. h. l. w. 



5. The Density and Atomic Weight of Neon. — A. Leduc, 

 starting with about 8 liters of this gaseous constituent of the 

 atmosphere, which was already nearly pure, purified it further by 

 fractional absorption by charcoal at the temperature of liquid air 

 followed by fractional expulsion until the final sample was 

 believed to contain less than T qW °^ impurities, chiefly nitrogen. 

 As a result of density determinations he found the value # 695 

 instead of 0-674 as found by Ramsay and Traver6. He found, 

 further, that the atomic weight of this element is exactly 20 times 

 that of hydrogen, or 20* 15 compared with oxygen as 16. This 

 value agrees closely with 20*2 given in the last International 

 table.— C. R., clviii, 868. h. l. w. 



6. A Chart of the Carbon Compounds ; by Charles W. 

 Cuno. Poster about 2|x3£ ft. (Published by the Author, 



