118 -S: p. Sadiler— Occurrence of Tartronic Acid, 



reckoning up the molecular weight, howe 

 atom of calcium to be present, I got 159. The molecular 

 weight of calcium tartronate is 158. Being dibasic, the molec- 

 ular weight of the calcium compound is of course much less 

 than the weight of the calcium compound of glyceric acid, a 

 monobasic acid. 



I endeavored twice to make a combustion of the salt in order 

 to get the per cent of hydrogen and carbon. Each time cal- 

 cium carbonate remained undecomposed at the heat of the 

 combustion. I therefore gave them up. 



I then took the remainder of my salt, grown rather small, to 

 my great regret, and neutralizing the lime with oxalic acid, 

 obtained the free acid. This, on concentral' 

 crystals. On examination with a lens they ' 

 tabular form, well agreeing with the appes 

 acid obtained from nitro-tartaric acid. A combui 

 made of these, and here, unfortunately, an accident to the 

 potash bulbs lost me the carbon determination. The hydrogen 

 determination, however, is given. 



•4348 grms. salt yielded 13-23 grms. H^O equal to 3'38 per 

 cent hydrogen. 



The theoretical per cent of hydrogen in C3H,03 is 3-33. 



An important test that I wished to make but was compelled 

 to forego for the time, was to act upon this tartronic acid with 

 hydrogen iodide. Were its structure symmetrical, it should 

 yield a iodo-malonic acid, which by further treatment with HI 

 or with reducing agents would yield malonic acid. 



Wishing to obtain larger quantities of the tartronic acid (or 

 further examination, I have since oxidized another portion of 

 glycerine and treated the products in the same way. This 

 time I got no tartronic acid whatever, at least only a trace of 

 calcium salt remained undissolved on heating with water. 

 Evidently here the oxidation had proceeded somewhat differ- 

 ently as no tartronic acid formed. This result is not surprising 

 on reflection, as the oxidation by nitric acid is not capable of 

 much control, and a product once formed is liable to be still 

 further oxidized. Thus glyceric and tartronic acids are both 

 liable to be oxidized into oxalic acid, which always forms in 

 considerable though varying quantity. Indeed the oxidation 

 of glycerine by nitric acid is now known to yield a variety of 

 products, of which, however, no doubt some are secondary 



Thus Heintz* has proved that racemic, formic, glycolic and 

 glyoxalic acids are all found associated with the glyceric and 

 oxalic acids in this product. 



The tartronic acid just found, therefore, is only one of sev- 



