280 The Philippine Journal of Science 1923 



a portion is lost in manipulation, the exact nickel content of 

 the catalyst was ascertained by analysis. 



The catalyst was analyzed by decomposing it with hydro- 

 chloric acid, evaporating, and dehydrating the soluble silicates, 

 after which they were eliminated by nitration. The nickel was 

 then precipitated as hydroxide with sodium hydroxide solution 

 in a large platinum dish, and weighed as oxide. The nickel 

 content of the various catalysts prepared for this work was 

 approximately 23 per cent. 



In hydrogenating oils the concentration of the catalyst in 

 per cent of nickel was calculated in the following manner: If 

 the catalyst contains 23.44 per cent nickel then 4.27 grams of 

 catalyst contains 1 gram of metallic nickel. In these experi- 

 ments 100 grams of oil were used for hydrogenation. If 4.27 

 grams of catalyst containing 1 gram of metallic nickel were used 

 to hydrogenate 100 grams of oil then the concentration of metal- 

 lic nickel for this quantity of oil was considered to be 1 per 

 cent. In all the experiments the concentration of the catalyst 

 was calculated in this manner. 



The catalyst was reduced in each case immediately before it 

 was mixed with the oil. The procedure was as follows: The 

 calculated quantity of catalyst was placed in a transparent 

 quartz combustion tube and spread out in a long thin layer. 

 Hydrogen gas, purified as previously stated, was passed through 

 the tube, which was gradually heated in a combustion furnace 

 to a temperature of about 300° (fig. 1). The exit end of the 

 combustion tube contained a trap, t, which served as a recep- 

 tacle for collecting the water given off during the reduction. 



*% 



The reduction was continued for a period of about fifteen 

 minutes, or until no more water was apparently given off. The 

 current of hydrogen was allowed to continue flowing through 

 the tube, which was now allowed to cool gradually to room 

 temperature. 



After reduction, the catalyst is oxidized readily when exposed 

 to the air and consequently loses to a considerable extent its 

 activity. In order to avoid exposing the catalyst to the air, a 

 current of carbon dioxide gas, which was purified by passing 



