Jones — Action of Carbon Dioxide on Soluble Borates. 443 



II 



III 



IV 



3a(OH) 2 taken. 















Calculated as 



B 2 3 



Weight of 



residue after 



B 2 3 





BaCOa. 



taken. 



successive ignitions. 



found. 



Error. 



grm. 



grm. 





grm. 



grm. 



grm. 



. 0-9391 



0*2200 



1st 



Wt. 



, 0-9860 



0-1263 



— 0-0937 







2d 



a 



0-9786 



0-IC63 



— 0-1137 



. 0-9318 



0-1295 



1st 



a 



0-9605 



0-0744 



— 0-0523 







2d 



a 



0-9558 



0-0646 



— 0-0649 







3d 



u 



0-9510 



0-0517 



-0 0778 



. 0-9253 



0-2192 



1st 



a 



1-0357 



0-2972 



+ 0-0780 







2d 



ts 



1-0248 



0-2679 



+ 0-0487 







3d 



a 



1-0149 



0-2412 



+ 0-0220 







4th 



a 



1-0064 



0-2183 



— 00009 







5th 



a 



09975 



0-1944 



— 0-0248 







6th 



a 



0-9855 



0-1621 



—0-0671 



. 0*7301 



0-0810 



1st 



u 



0-8017 



0-1927 



+ 0-1117 







2d 



a 



0-7777 



0-1281 



+ 0.0471 







3d 



a 



0*7642 



0-0918 



+ 0-0108 







4th 



a 



0-7582 



0-0757 



— 0-0053 







5th 



a 



0-7517 



0-0582 



— 0-0228 







6th 



a 



0-7482 



0.0487 



— 0-0323 







7th 



u 



0-7447 



0-0393 



— 00417 







8th 



a 



0-7427 



0-0339 



-00471 







9 th 



a 



0-7422 



0-0326 



— 0-0484 







10 th 



a 



0-7407 



0-0285 



— 0-0525 



Plainly the results vary with the degree of the ignition. 

 At the outset the residue may or may not weigh more than the 

 theory requires for the known amounts of barium hydroxide 

 and boric acid taken upon the assumption that the residue is 

 barium metaborate and barium carbonate. This is obviously 

 natural, if the carbon dioxide acts upon the barium borate as 

 well as upon the excess of barium hydroxide ; for, it is to be 

 expected that in the evaporation more or less of the free boric 

 acid will volatilize, and that in the subsequent ignition the boric 

 acid remaining will tend to recombine more or less com- 

 pletely, replacing carbon dioxide. If the boric acid present 

 were to recombine completely with the barium carbonate to 

 form a metaborate, the final result would always be low by just 

 the amount of free boric acid volatilized in the process of 

 evaporation and ignition. The evidence of an experiment, 

 however, in which 0-25 grm. of previously prepared barium 

 metaborate was fused in contact with 05 grm. of barium car- 

 bonate, resulting in a loss of 0*0871 grm., goes to show that 

 the metaborate and carbonate of barium interact still further 

 to liberate carbon dioxide. 



These results were so surprising in the light of the experi- 

 ence of Morse and Burton that the question of the possibility 

 of breaking up by carbon dioxide the barium metaborate 



