October 13, 1922] 



SCIENCE 



427 



and leaf presses completely fail to apply in the 

 case of sludges -which are highly compressible and 

 those to which filter-aids have been added. Care- 

 ful experimental study of the problem has been 

 made and empirical formulae developed which are 

 believed to be satisfactory for the problems of 

 engineering design. 



Behavior of compressible sludges during filtra- 

 tion: M. P. AVooDWARD and W. J. Edmonds. 

 Careful study has been made of the resistance to 

 flow of liquid through sludges of different tj-pes 

 as a function or pressure, pressure gradient and 

 time of filtration. On the basis of the experi- 

 mental results fundamental differential equations 

 have been derived. One method of solution of 

 these equations has been suggested. 



The solvent properties of aeetone: B. P. Bem- 

 LER. The paper takes up the following industrial 

 consideration regarding acetone as a solvent; uni- 

 formity of the present grade of acetone from 

 calcium acetate, boiling point and volatility, 

 freezing point, inflammability, dehydrating prop- 

 erties, miscibility with other solvents, use as a 

 coupling or bending agent between immiscible 

 solvents, relative cost per gallon, physiological 

 effects and recovery of vapors. The solubility of 

 acetylene, cellulose acetate and cellulose nitrate, 

 rosin and mineral oils, gums, resins, shellacs, 

 animal and vegetable oils, fats and greases, waxes, 

 asphalts and bitumens are discussed. Mention is 

 also made of acetone in the dry cleaning and 

 leather industry as a constituent of paint, var- 

 nish and carbon removers. 



Bosin determination in pine products: A. H. 

 ViLBRANDT and James B. Withrow. The deter- 

 mination of rosin in various mixtures, such as 

 pine oils, wood creosotes and kerosene mixtures 

 for materials used as fly chasers or in emulsions 

 for disinfectant purposes is a matter of well- 

 known importance. Eesults frequently reported 

 by manufacturers and consumers are discordant. 

 The writers have found, however, that the stand- 

 ard methods, with but slight modification for the 

 prevention of emulsions, give results which are 

 accurate- easily within % of 1 per cent, and 

 sometimes much more accurate than this. 



Some industrial uses of ozone: Er^^in W. 

 Pelkel. The use of ozone in the industries has 

 not been widespread due to two reasons, viz., 

 (1) A satisfactory source has not been obtain- 

 able, and (2) on account of the high cost of pro- 

 duction. For the past several years ozonizers 

 furnishing a large amount of ozone at a low con- 

 centration have been developed, and these ma- 

 chines have demonstrated their durability. The 



advent of the commercial ozonizer has opened two 

 fields for the industrial application of this gas: 

 (1) in places where a small amount of ozone will 

 accomplish the desired result and (2) in the pro- 

 duction of products that sell for a sufficiently 

 high price to justify its use. In the first class we 

 have the bleaching and oxidizing of vegetable 

 drying oils and the drying of paints and var- 

 nishes. In the second class is the production of 

 certain aromatic aldeJiydes and the production of 

 potassium permanganate. Small amounts of 

 ozone at low temperatures bleach an alkali re- 

 fined- linseed oil almost colorless, while if the tem- 

 perature be raised the major effect is one of 

 oxidation. The drying of varnishes is also an 

 effect of oxidation. This oxidation is antocata- 

 lytic and can be greatly hastened by the presence 

 of exceedingly small quantities of ozone in the 

 atmosphere of the drying room. The production 

 of vanillin is a straight chemical reaction in 

 which the ozonide of isoeugenol is made and sub- 

 sequently reduced. The production of potassium 

 permanganate is accomplished by oxidizing potas- 

 sium manganate in alkaline solution. 



Methanol from methane: Ealph H. McKee and 

 Stephen P. Burke. By passing methyl chloride 

 mixed with steam over slaked lime cvt 375° G. 

 there is obtained a 90 per cent, conversion into 

 methanol (65 per cent.) and methyl ether (25 

 per cent.). By passing steam and methyl ether 

 over aluminium oxide at 350° C, methyl ether is 

 half converted to meithyl alcohol. By reworking 

 the residual methyl ether this conversion can. be 

 made complete. The presence of an inert gas, 

 e. g., methane, is not a hindrance to the process. 

 All operations are carried through without pres- 

 sure and can be arranged to w'ork in a continuous 

 operation. Accordingly we have now available 

 to supplement our failing methanol supplies a 

 process which incompletely chlorinates a high 

 metliane natural gas, hydrolyzes the methyl chlo- 

 ride content of same to methanol and methyl 

 ether and reworks the methyl ether to give a final 

 yield of methanol of 90 per cent, of the methyl 

 chloride first made. 



The examination of writing inks: P. P. Eupert. 

 There is need of a system of examination of 

 writing inks which shall proceed on scientific 

 principles and at the same time be related to the 

 needs of the average user of ink, and this paper 

 attempts to provide such a basis. The four quali- 

 ties of writing inks most desired are color, per- 

 maneiiey, stability and non-corrosiveness, and 

 these should be given consideration in approxi- 

 mately equal degree. The relation of composition 



