August 10, 1917 



SCIENCE 



145 



Bunsen, which is based ou the fact that the specific 

 gravity of two gases Ijear approximately the same 

 ratios to each other as do the squares of their rate 

 of flow when passing through a very small open- 

 ing. The apparatus consists of a pipette or burette 

 to which is sealed at right angles, just below the 

 tip, a glass stopcock. To the tip of the burette 

 another stopcock is sealed which is provided with a 

 very small, practically invisible opening. The gas 

 to be examined is admitted through the larger side 

 opening and the time of escape is measured 

 through the small opening. A sample of air is 

 measured in the same manner. The following ex- 

 ample will serve as an illustration: The time re- 

 quired for the sample of gas to escape was 13.4 

 seconds and for the same quantity of air, 11.8 sec- 

 onds; these squared are equal to 190.4 and 129.9. 

 As the specific gravity of natural gas is referred 

 to aii- as unity, the specific gravity is obtained by 

 dividing 129.9 by 179.5 = 0.723 the specific grav- 

 ity of the gas. 



Comparative results from experiments in the 

 distillery with open and closed fermenters : Niels 

 C. Ortved. a closed iron fermenter of the latest 

 type with a capacity of 4,000 liters was brought 

 from Germany in 1914 and a wooden open tub of 

 the same capacity was constructed. Eleven experi- 

 ments were made, fermenting simultaneously mash 

 from the same batch in both vessels. The results 

 obtained were in favor of the closed fermenter, 

 viz., lower acidity in the finished beer, and in- 

 creased yield, amounting to one per cent, of spirit. 

 The yields from the open fermenter corresponded 

 to the average yields obtained in the ordinary nor- 

 mal runs of the distillery. 



The effects of exposure of some fluid Mtumens: 

 Chables S. Reeve and Eichaed H. Lewis. The 

 work described was a continuation of that begun 

 by Hubbard and Reeve (Jour, of Indus, and Eng. 

 Chem., 1913), and of later results published by 

 Reeve and Anderton in the Journal of the FranTc- 

 lin Institute, October, 1916. Experiments were 

 carried out along similar lines to those previously 

 followed, using fluid types of products which had 

 not been previously investigated. Exposure tests 

 conducted for a period of one year show that cer- 

 tain types of petroleum harden materially while 

 others are relatively little changed in their phys- 

 ical character, although all are materially changed 

 in their composition as shown by the change in 

 percentage of bitumen insoluble in naphtha and 

 free and fixed carbon values. The relation be- 

 tween amounts volatilized upon heating for vari- 

 ous periods in a laboratory oven at 163° C. and the 



amounts lost upon atmospheric exposure were 

 shown by tables, and relations between the charac- 

 ters of the residues obtained by the two methods 

 of volatilization were given. As in the previous 

 work referred to, the changes which occur in bi- 

 tumens upon exposure are notably greater than can 

 be accounted for by mere loss of volatile constitu- 

 ents, and are due to chemical changes in the con- 

 stitution of the bitumen itself. 



The thermal and pressure decomposition of an 

 absorbent oil: Gustav Eglopt. An absorbent oil 

 derived from a Pennsylvania crude petroleum, 

 specific gravity 0.828/15.5° C. and 95.3 per cent, 

 boiling between 250° C. and 350° C. was subjected 

 to temperature conditions of 550° C, 600° C. and 

 650° C. in the gas phase at one and eleven at- 

 mospheres pressure. The above conditions of tem- 

 perature and pressure gave the following per- 

 centages of gasoline, benzene, toluene and zylenes 

 on basis of oil used. 



The formation of benzene and toluene hy the ac- 

 tion of aluminum chloride on solvent naphtha: 

 Gustav Egloft. Solvent naphtha derived from 

 the thermal decomposition of coal, having a spe- 

 cific gravity of 0.867/15.5° C. and 93 per cent, dis- 

 tilling between 135° and 160° C. with the dry 

 point at 181° C. was treated with anhydrous 

 aluminimi chloride. Five per cent, by weight of 

 AICI3, was added to one liter of solvent naphtha 

 and distilled over in two hours from a Hempel 

 flask until 78 per cent, came over. The distillate 

 was neutralized with caustic, washed and dried 

 over calcium chloride. The distillate upon analysis 

 gave on the basis of solvent naphtha used 1.2 per 

 cent, of benzene and 13.9 per cent, of toluene. 



The determination of available oxygen in oxi- 

 dized manganese ores: O. L. Baenebet. The 

 oxalic acid method is in common use in America 

 for the determination of avaOable oxygen in oxi- 

 dized manganese ores and hence is the basis for the 

 evaluation of such ores for certain industrial pur- 

 poses. This method gives inconsistent results 

 causing much difficulty in control work involving 

 the use of pyrolusite and similar products. The 



