58 THE ROYAL SOCIETY OF CANADA 



were formed for 24 hours with 0.25 amp. (badly sulphated) followed 

 by higher currents (mostly one ampere) for 36 hours. Their 

 efficiency was 80% and weight 293 g. per ampere hour. With- 

 out glycerine the efficiency was 76% and weight 521 g. 

 (Under direction of Professor J, T. Burt-Gerrans) 



(16) The Preparation of Boron Carbide from Boric Acid and Carbon 

 in the Electric Furnace 



By J. M. Logan 



Boric acid was mixed in different proportions with graphite, 

 charcoal, or electrode carbon and heated to different temperatures 

 (measured with the pyrometer) from 800°C to 1,800°C, in closed 

 carbon tubes or plumbago crucibles, by means of a granular carbon 

 resistor electric furnace; some runs were made in the Moissan arc 

 furnace. In the product boron was determined as loss when heated 

 with chlorine in a combustion tube, carbon by burning the residue in 

 oxygen, ash as the final residue; iron was determined in a separate 

 sample. The best results were obtained by two hours heating at 

 temperatures exceeding 1,800°C in crucibles turned from 4 inch 

 carbon electrodes covered with a lid of the same material threaded on 

 and luted with a mixture of powdered coke and sodium silicate. 

 Crystals of the same form were obtained whether carbon or boric 

 acid was present to an excess of 25%. 



(Under direction of Professor J. T. Burt-Gerrans) 



(17) A Method for the Rapid and Accurate Estimation of Copper in 

 White Alloys and Babbit Metals 



By E. W. McHenry 



High grade babbits (low in lead) are dissolved in 10 c.c. cone, 

 hydrochloric acid (for one gram metal) with addition on 25 c.c. 

 tartaric acid solution (30 g. to 100 c.c.) and as little nitric acid as is 

 needed to effect solution. The solution is diluted to 55 c.c, cooled, 

 and after addition of 30 c.c. ammonia (0.880) cooled again, and 

 titrated very slowly (about four minutes) with standard potassium 



