April y til, /poc?.] Proceedings. xxiii 



then in ether, the effect could not be removed. By boiling, how- 

 ever, in a dilute solution of caustic soda for a few minutes, all trace 

 of the action of the oxalic acid vanished, without any tendering 

 of the fabric being noticeable. This observation precluded, there- 

 fore, the possibility of the formation of oxycellulose. It almost 

 appeared as if some of the oxalic acid had combined with the 

 cellulose to form an oxalate, which, by analogy with the nitrates, 

 acetates, &c., would show the characteristic behaviour towards 

 dyestuffs. I was unable, however, to detect oxalic acid in the 

 caustic soda extract of the treated fabric, and for some time 

 gave up the work. 



On resuming my investigation into the subject, I was led to 

 test the caustic soda extract of the treated fabric for formic 

 acid, which was found to be present. It would therefore appear 

 that in drying the oxalic acid had undergone decomposition into 

 carbonic acid and formic acid, which latter had in the nascent 

 state combined with the cellulose. Attempts to determine 

 quantitatively the actual amounts of cellulose formiate produced 

 were not satisfactory, the results obtained being very irregular. 

 In any case, however, the amounts found appear to be only 

 small. 



This explanation of the action of oxalic acid on cellulose 

 becomes all the more probable from the results of further 

 experiments with malonic acid and hexylmalonic acid, both of 

 which behave like oxalic acid, and this would be expected from 

 their behaviour on heating. In the saponification product from 

 cotton treated with malonic acid, it was possible to detect 

 acetic acid. 



Succinic acid, on the other hand, does not show any altera- 

 tion in the cellulose, nor does glutaric acid. 



It would appear, therefore, that the action of oxalic acid on 

 cellulose simply constitutes one example of a general mode of 

 formation of acidyl celluloses. 



Professor Knecht also exhibited specimens of commercial 

 metallic titanium and commercial silicon. 



In a discussion which took place later Mr. Julius Hubner 



