Nitrogen Thermometer from Zinc to Palladium. 157 



Silicon. — 10 g. metal were dissolved in a mixture of nitric 

 and sulphuric acids, using a platinum dish. With hydrochloric 

 acid alone nearly all the silicon is lost as hydride. The brown 

 amorphous residue was iiltered, washed and fused with sodium 

 carbonate. From the fusion silica was obtained in the usual 

 way. Si0 2 =41*4 mg. Si=0*194 per cent, liepetitions gave 

 0*189 per cent and 0*190 per cent. 



Carbon. — 10 g. metal were dissolved in NaOH and filtered 

 through glowed asbestos, washed first with water, then with 

 dilute acid and finally with water and dried at 105°. The 

 asbestos and residue were then transferred to a combustion 

 tube and burned in air free from C0 2 . The gases were passed 

 through standard Ea(OH) 2 . A considerable precipitate was 

 obtained, while a blank gave no trace. The excess of Ba(OH) 2 

 was the ntitrated with standard acid using phenolphthalein as 

 indicator.' 5*05 mg. C0 2 found. C = 0*014 per cent. A 

 duplicate in which the metal was dissolved in KOH gave 

 0*012 per cent. 



Iron. — 10 g. metal were dissolved in hydrochloric acid, and 

 to the solution was added tartaric acid free from iron. From 

 this solution the iron was precipitated by colorless ammonium 

 sulphide. The precipitate was finally changed to sulphate 

 and determined volumetrically. Fe = 4*6mg. Blank deter- 

 mination gave 0*3 mg. Fe = 0*043 per cent. 



Calcium, Sodium, and Potassium were sought for in the 

 hydrochloric acid solution, by precipitating with ammonia, 

 washing the large precipitate and testing the evaporated filtrate. 

 No Ca. Some alkaline chloride was found, but a blank showed 

 that it came from the ammonia, as there was only a difference 

 of 1*6 mg. between the chloride of the blank and that in the 

 determination. No Na or K. 



Analysis of Aluminum. 



As none C 0*013$ 



Sb " S._ 0-002$ 



P " Ca none 



Cu ,0*003$ Na _ " 



Fe 0*043$ K 



Si 0*190$ 



0-251$ 



Antimony. 



25 g. metal were powdered in an agate mortar and treated 

 with 35 per cent HNG 3 on the steam bath. As soon as the reac- 

 tion was practically complete, the antimonic acid was extracted 



Am. Jour. Sci.— Fourth Series, Vol. XXIX, No. 170.— February, 1910. 

 11 



