BORON AND FLUORINE. 39 



of this decomposition by heat. Of course there were some mis- 

 givings as to the propriety (in atomic weight work) of the last 

 step in this method; nevertheless it was given a trial. It was 

 possible to prevent the ignition of the hydrogen and carbon 

 monoxide produced in this decomposition and to obtain colorless 

 sodium carbonate as an end-product. However, at the same time 

 it was noticed that this decomposition was accompanied invari- 

 ably by a slight mechanical loss, even when the reaction was 

 conducted very slowly and with the greatest care, in the long- 

 necked platinum bulb and in an atmosphere of carbon dioxide. 

 At certain stages in this decomposition, evidently a very fine 

 dust or "mist" of the sodium salt itself was formed, traces of 

 which escaped from the bulb and thus caused the loss referred to. 

 Such phenomena are not particularly surprising in reactions of 

 this sort that is to say, in decompositions by heat which involve 

 a rather violent rearrangement within the molecule. Similar 

 difficulties have been met with in the ignition of other substances, 

 such as the chlorates. It is therefore evident that the quanti- 

 tative conversion of sodium formate into the carbonate by 

 ignition was practically out of the question, unless perhaps the 

 entire apparatus had been subjected to a radical modification. 



Another possibility which suggested itself was the following: 

 The saponification of a suitable ester of carbonic acid, say methyl 

 carbonate, by borax, with the simultaneous production of sodium 

 carbonate and the methyl ester of boric acid. Methyl carbonate 

 was prepared by allowing an ethereal solution of methyl iodide 

 to react, at a gentle heat, with dry silver carbonate in a flask 

 provided with a reflux condenser. The first distillate was frac- 

 tioned a few times, and the fraction finally collected boiled at 

 90.5. The yield was poor, but the quantity obtained (about 5 

 grams) was sufficient for a trial. A sample of fused borax was 

 then dissolved in water, evaporated to dryness, and evaporated 

 a number of times with a solution of methyl carbonate in methyl 

 alcohol, while a current of air, free from carbon dioxide, was 

 passed through the apparatus. The residue was finally tested for 

 combined carbonic acid, but only a bare trace could be detected. 

 The original borax was entirely free from carbonates; the trace 

 just mentioned had probably been introduced by a little carbon 

 dioxide in the water used in the first evaporation. The methyl 



