450 PROFESSOR W. DITTMAR ON THE BEHAVIOUR OF THE 





A. 



B. 



C. 



Substance, . 



5-2502 



5-2520 



5-0723 



Carbonic acid, 



31315 



3-1265 



3-0259 



Percentage of C0 2 , 



59-645 



59-529 * 



59-655 



Experiment D. — Carbonate kept fused under carbonic acid of 30*24 inches pres- 

 sure for one hour. The chloride of barium test proved the absence of caustic lithia. 

 Carbonic acid not determined. 



Experiment F. — Substance prepared as in case D, only the outgoing gas was not 

 made to bubble through mercury; the barometer stood at 29*2 inches. 67288 grm. 

 gave 3*9559 grm. of carbonic acid, or 58*790 per cent. This number almost proves 

 the presence of caustic lithia, but to make sure of this the chloride of barium test was 

 applied (this time in only a roughly quantitative fashion); it showed that there was 

 upwards of 0*6 per cent, of free lithia. 



Experiment G. — A quantity of carbonate was fused under carbonic acid of (Bar. + 

 extra mercury =) 30*24 inches pressure for one hour. The experiment was made twice 

 to obtain a sufficiency of material for an analysis on a large scale. 4'2220 grm. gave 

 2*5198 grm. of carbonic acid, or 59*683 per cent. 



Experiment H. — Carbonate of lithia was fused under carbonic acid, first for 

 one hour at a pressure of 30*1+2 = 32*1 inch, then for half an hour at a pressure 

 of 60*1 inch. 1*2984 grm. gave 0*7809 grm. of carbonic acid, or 60*143 per cent. 



Experiment J. — Done in the same way as H ; actual pressure in the final stage = 59*94 

 inches. 3*8206 grm. of product gave 2*2845 grm. of carbonic acid, or 59*794 per cent. 



Experiment K. — Again, by intention, a repetition of H. Final pressure = 59*96 

 inches. 2*527 grm. of product gave 1*5057 grm. of carbonic acid, or 59*584 per cent. 



Experiment L. — Carbonate of lithia was heated in carbonic acid, first for one hour 

 under 2 inches of extra pressure, then for half an hour under 15 inches: or about 45 

 inches of total pressure. This product was not analysed, because it consisted, part of 

 a solid glassy fuse, part of glassy particles, and part of a dull powder. In Experiments 

 J and K also the product did not present itself as a compact fuse, but in the form of 

 glassy particles, which looked as if they had been produced from what was originally a 

 fuse by spontaneous disintegration on cooling. But my subsequent experience enables 

 me to affirm that fused carbonate of lithia, even if produced under pressure, is not 

 subject to such disintegration. The aspect of product L showed that the temperature 

 which prevailed in the tube, in that experiment at least, was not sufficient to produce 

 a homogeneous fuse, hence the apparatus was transferred to another room which afforded 

 a better gas pressure, and the work continued there. For 



Experiments M, N, and P, the substance for analysis was prepared as in the case 

 of H, except that the pressure in the final stage of the heating process was not 

 necessarily the same. The exact values of these pressures, and the results of the 

 analyses, are given in the following table : — 



* This analysis did not proceed quite regularly; yet I have no reason to suspect that the result is at all far out. 



