[miller] chemical LABORATORY RESEARCHES 51 



The Passage of Hydrogen and Helium through Silica Tubes 



By Professor J. B. Ferguson and G. A. Williams, B.S. 



Presented by Professor W. Lash Miller, F.R.S.C. 



The rate at which hydrogen passes through transparent (not 

 devitrified) silica-glass tubes at 440°C is 1.5 X 10-" c.c. (0°,760mm.) 

 per hour per sq. cm., the external pressure being one atmosphere and 

 the internal pressure a few hundredths of a mm. At 628°C, 5 X 

 10-''- c.c, and at 727°C, 8 X 10-" c.c. For external pressures of 

 0.5 to one atmosphere the rate is proportional to the pressure differ- 

 ence; for 0.25 atm. the rate is somewhat greater than this relation 

 would lead one to expect. Pyrex glass and (German) combustion 

 tubing were impermeable; the pyrex blackened. Helium at 632°C 

 diffused through the silica-glass at least five times as rapidly as 

 hydrogen. Air does jiot pass at temperatures up to 800°C and 

 pressures up to one atmosphere. 



Researches Carried out in the Chemical Laboratory of the University of 

 Toronto during the Session 1920-1921 



Presented by Professor W. Lash Miller, F.R.S.C. 



(1) The Intermediate Compounds in the Reaction between Phthalic 

 Anhydride, Benzene and Aluminium Chloride and their Use in the 

 Synthesis of Mixed Phthalides. 



By T. C. McMuLLEN, B.A. 



One of these intermediate compounds has been isolated and 

 analyzed. It is almost impossible to get this intermediate compound 

 pure and it is very easily hydrolysed but the analyses approximate to 

 the formula: CHH9O3AI2CI5 after prolonged drying in the vacuum 

 oven. 



This intermediate compound may be used either for the prepara- 

 tion of benzoyl-benzoic acid or for the preparation of diphenyl- 

 phthalide and if a different hydrocarbon is used with the intermediate 

 compound a mixed phthalide is formed as, for example, phenyl 

 tolylphthalide. Several of these mixed phthalides have already been 

 obtained. (Under direction of Professor F. B. Allan) 



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