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THE ROYAL SOCIETY OF CANADA 



absorption of moisture. To obtain information on this point the 

 following experiment was carried out. Six samples of the same flour 

 were weighed out and heated for 3| hours in the vacuum oven at 

 100°C. At the expiration of this period three of the dishes were 

 quickly transferred to the electric air oven (temperature 100°C.) and the 

 three remaining dishes were cooled and weighed without delay. The 

 results were as foUow^s: 



Comparison of results from dryingin Vacuum oven and Vacuum and Air ovens, 



at IOO°C. 



These results prove the correctness of the conjecture. 

 Summary: The work detailed in this paper permits, in the 

 opinion of the authors, the following conclusions: 



1. That the lower results obtained by heating flours to constant 

 weight in an air oven at 100°C. as compared with those from drying 

 in a vacuum oven at the same temperature, are not due to oxidation 

 of the flour. They point rather to incomplete drying. 



2. That throughout this investigation it has appeared that 

 drying flour in a vacuum oven at 100°C., say for 5 hours, possesses 

 the following points of advantage as compared with drying in an air 

 oven at the same temperature to constant weight. 



1. That it gives results nearer the absolute moisture content 

 of the flour. 



2. That duplicate and triplicate samples show a closer agreement. 



3. That results are obtained in a much shorter drying period. 



