decomposed by carbon dioxide. Wislicenus proposes the 

 formula 



CH2.CO.CH.CO.O.C,H, 



CHg.CO.CH.CO.O.C^H, 



for the original compound, according to which it is ethyl 

 succinylsuccinate, a derivative of succinylsuccinic acid. The 

 metallic compounds are explained by supposing the hydrogea 

 atoms of the groups CH to be replaced by the metals, the 

 hydrogen in thcvse groups having a somewhat acid character. 

 It seems to me that the great stability of the ether which we 

 have above recognized speaks against this formula. Most 

 acids, which cttnsist of atoms grouped in the manner indicated 

 by the above formula, are decomposed by boiling with baryta- 

 water, whereas we have seen that this substance may be boiled 

 with baryta-water without undergoing decomposition. It is 

 true that we know very little concerning bibasic acids of this 

 structure, and it is possible that what is true of the monobasic 

 acids is only partially true of the bibasic. Be this as it may, it 

 is certain that the experiments thus far published will not per- 

 ! conclusion that the above formula is the true 

 [ further investigations would be called for whether the 

 formula is correct or not. 



3. Action of phosphoric Chloride upon the body C, ^H, gO^. 



With the hope of learning something more definite concern- 

 ing the nature of the oxygen-atoms contained in the substance 

 under examination, I next undertook the study of the action of 

 phosphoric chloride upon it. At first I employed two mole- 

 cules of the chloride to one molecule of the substance. When 

 the two are brought together in a dry vessel, no action ensues 

 until heat is applied. If the mass is very gently heated, the 

 substance C.aH.gOa melts, and immediately reaction com- 

 mences, and continues then without the further aid of heat, 

 until the contents of the retort form a clear, hon: 



le posit] 

 nd furtl 



j-ne reaction is accompanied by an evolution of chlorhydric 

 acid, the amount of which, however, was such as to leave me 

 in doubt whether this was a necessary product of the reaction, 

 or was formed from the secondary decomposition of the phos- 

 phorus compound which distilled over. The oxichloride of 

 phosphorus was distilled off by gentle heat, and the oil in 

 the retort then treated with water. Decomposition soon began 

 and there resulted a solid, insoluble product. On examination 

 this proved to be the original substance CjaH, ^0^. As the 

 amount of this product was comparatively considerable, I at 

 once concluded that a chloride had been" formed by the first 

 reaction which by its decomposition with water yielded the 



