160 RESEARCHES UPON THE CHEMICAL PROPERTIES OF GASES. 



ing alcohols towards reducing agents. Methyl alcohol is decomposed on warming 

 with powdered zinc, with formation of CO and H, while ethyl alcohol is unaltered 

 except at a red heat (Jahn, Qrundscitze der Thermochemie, p. 150). 



4. Propane. — This hydrocarbon was prepared by Gladstone and Tribe's method, 

 from isopropyl iodide and " copper-zinc couple." The reaction is much slower than 

 in the case of methane and ethane ; the yield is, however, satisfactory. The same 

 method of purification was used as in the case of methane. The gas was found to 

 be free from iodine compounds. 



JExpt. 14. Palladium Asbestos. — 



Propane 3. 1 



Air 96.9 



Oxidation occurred at the following temperatures : 



(1) Above melting point of potassium nitrate (339°). 



(2) Just below melting point of potassium nitrate (339°). 



(3) " above " " " " " (339°). 



(4) Just below melting point of lead iodide (3830). 



(5) At melting point of potassium chlorate (359^). 



(6) " " " " " " (3590). 



5. Isobutane. — This hydrocarbon was prepared by the method of Gladstone 

 and Tribe from isobutyl iodide and " copper-zinc couple." It was purified by the 

 method followed in the case of the preceding hydrocarbon, and was proved to be 

 free from iodine compounds. 



JExpt. 15. Palladium Asbestos. — 



Isobutane 3. 1 



Air ■ 96.9 



Oxidation occurred at the following temperatures : 



(1) At 236^ (3) At 350O (5) At 235° 



(2) " 325^ (4) " 220° (6) " 250'^ 



Pxj^t. 16. — The same mixture of air and isobutane was conducted over ruthen- 

 ium asbestos (prepared by the use of ruthenium chloride in the same manner as the 

 palladium asbestos already described). Oxidation occurred at the following tem- 

 peratures : 



(1) At 250° (3) At 230O (5) At 222° 



(2) " 236'^ (4) " 2250 (6) " 214>^ 



As regards this more easily oxidizable hydrocarbon ruthenium and palladium 

 have almost the same action, 



6. Pentane. — Petroleum gasolene, which had been kept several weeks in con- 

 tact with concentiated sulphuric acid, was fractionated and the fraction, boiling at 



