58 C. U. C. P. ALUMNI JOURNAL April, 1918 



KBSTRT^OXS 



Conducted by Prof^ George C. Diekman. 



Nitro-derivatives of Toluene 



T. Kidokoro, in Kogyo-Kwagaku-Zasshi, (J. Cheni. Ind., Tokyo, 1917, 20,) 

 presents the subject in part as follows: — ortho-nitrotoluene is best prepared by 

 adding- a mixture of i part of nitric acid (S/G. 140) and 2 parts of sulphuric 

 acid, (S/G. 1.84), to i part of toluene, keeping the temperature at 30° C. for 6 

 hours, and constantly stirring. The product is washed with water and dilute 

 alkali solutions, and then distilled in vacuo. The yield is about 55.1% of the 

 theoretical. Para-nitrotoluene may be obtained by nitrating i part of toluene with 

 2 parts of fuming nitric acid (S/G. 1.47) at ordinary temperature, for 15 hours, 

 purifying in a manner similar to that employed for the ortho compound. The 

 yield is about 6o7o of the theoretical. 2-4 dinitrotoluene is prepared by adding 

 230 mils of nitric acid to no mils of toluene, at the ordinary temperature, under 

 stirring. The mixture is then cooled, and 230 mils of sulphuric acid (S/G. 1.84) 

 are added. This mixture is then warmed on a water bath for 30 minutes, cooled 

 to 0° C, and the crystals of dinitrotoluene recrystallized from alcohol. The yield 

 is found to be almost 98% of the theoretical, the melting point of the compound 

 is at 71° C. 2-4-6 trinitrotoluene is obtained by dissolving 40 grammes of dini- 

 trotoluene in 88 mils of sulphuric acid, (S/G. 1.84), and adding 40 mils of nitric 

 acid (S/g. 1.52). This mixture is heated on the water bath for a period of 4 to 

 5 hours, or until the evolution of gas ceases. The yield represents about 96% 

 of the theoretical. 



Foreign Oils in Castor Oil 



Since it has been found that castor oil is by far the best hibricating substance 

 to be used for aeroplane motors, the matter of detecting additions of foreign oils 

 has assumed more than usual importance. C. Frabot, in Ann. Chim. Analyt, 1917, 

 22, makes the following observations: — By determination of the acetyl value it 

 is possible to detect the presence of from i per cent, to 2 per cent, of added oils, 

 the other physical constants are of little or no value in this direction. When 

 arachis oil serves as the adulterant, to the limit of 5 per cent., the alcohol solu- 

 bility and the solidification were found to be of most value. It is feasible to de- 

 termine the turbidity temperature for smaller amounts of added arachis oil. It 

 is found that a solution of i volume of castor oil in 95 per cent, alcohol, when 

 chilled to — 20° C., remains perfectly clear. The addition of 2 per cent, of arachis 

 oil caused the mixture to become turbid at from — 2° to — 3° C., while a sample 

 containing 5 per cent, of this admixture, becomes turbid at from +5° to +6° C. 

 Castor oil containing I per cent, of arachis oil, when in alcoholic solution, be- 

 comes opalescent at from —4° to —5° C, and decidedly turbid at — 9° C. The 



