486 Scientific Intelligence. 



7. On the Occurrence of Platinum^ Palladium^ and Selenium 

 in Silver coins.— In a letter to Wohler, Rosslee, of the Frank- 

 fort parting office, gives some facts of interest relative to the work 

 done in that establishment. During the last year over 400,000 

 pounds of silver and 5,000 pounds of gold were parted. The 

 silver is purified by crystallization as sulphate and subsequent re- 

 duction to the metallic state by iron turnings. The gold is precip- 

 itated from its solution in aqua regia by ferrous chloride and 

 melted in gas furnaces; being obtained 1000 fine in this way. 

 Fine silver, especially that obtained from old coins, contains gold 

 averaging about one-thousandth. It also contains both platinum 

 and palladium, the latter sometimes in so large a quantity that its 

 solution in nitric acid is dark yellow. The silver from Commern 

 and Mechernich in the Eifel showed 0*0058 per cent platinum and 

 0-0053 per cent palladium. In the last year, the office has obtained 

 from the 500,000 pounds of crude silver worked over, twelve 

 pounds of platinum and two pounds of palladium. To obtain 

 these metals, the solution, from which the gold has been precipita- 

 ted by ferrous chloride, is reduced again by iron turnings, whereby 

 all the other metals present are precipitated as a black sediment. 

 This is freed from copper by the iron chloride, the residue is dis- 

 solved in aqua regia, the traces of remaining gold are removed, 

 the platinum is thrown down by ammonium chloride and the pal- 

 ladium by ammonia and hydrochloric acid. In this way selenium 

 was discovered in this deposit. Since then the sediment is fused 

 with soda and charcoal before treating it with aqua regia ; several 

 pounds of selenium a year being obtained from this source. The 

 selenium forms an interesting compound with palladium, which is 

 obtained in hard brilliant plates when the regulus obtained as 

 above is dissolved. These plates are not soluble in nitric acid, 

 nor, when platinum is present, in aqua regia ; but on ignition they 

 evolve selenium and are then soluble. They are composed of 

 equal atoms of palladium and selenium and resemble the iridos- 

 mine scales very closely, being isomorphous with them. — i^«- 

 big's Ann., clxxx, 240, Feb., 1876. g. f. b. 



8. On the Conversion of Olejines into the corresponding Alco- 

 hols. — The considerable siniilarity between the heptylene obtained 

 from pentamethyl-ethol and the terpenes led Boutlekow to 

 attempt the direct synthesis of the alcohol from the olefine by 

 direct union with water, just as the hydrate of terpin is formed. 

 The heptylene was sealed in a tube with water containing a little 

 nitric acid and alcohol. After a few weeks the heptylene had dis- 

 appeared and had been replaced by the characteristic crystals ot 

 pentamethyl-ethol. Liquid isobutylene was then subjected to a 

 similar treatment and with a similar result ; trimethyl-carbinol 

 was produced. Sulphuric acid was found to act upon isobutylene 

 in the same way. This olefine, sealed in a tube with double its 

 volume of a mixture of equal parts concentrated sulphuric acid 

 and water, disappeared in the course of two days, and yielciea 



