436 PROCEEDINGS OF THE AMERICAN ACADEMY. 



II. 0.2177 gi-am of the substance gave on combustion 0.4181 gram 

 of carbonic dioxide. The water determination was lost. 

 III. 0.1843 gram of the substance gave by the method of Carius 

 0.1304 gram of argentic chloride. 

 IV. 0.1 G20 gram of the substance gave 0.1135 gram of argentic 

 chloride. 



Calculated for Found. 



CoCl,(OC,,U.,),(OCaH5)i. I. 11 III. IV. 



Carbon 52.30 52.54 52.37 



Hydrogen 7.26 7.28 — 



Chlorine 17.19 17.49 17.32 



The yield, as has been already stated, is very small. 



Properties of Dlchlordiethoxyquinone Tetraetliylacetal. — This sub- 

 stance can be obtained from ligroine in good-sized white rhombic 

 prisms, but when more rapidly crystallized it forms irregularly fan- 

 shaped groups of very much branched needles resembling certain 

 delicate seaweeds, or four-sided plates nearly but not quite rectangu- 

 lar and much striated. It melts at 101°-102°. Bv heating in a 

 ca[)illary tube it is ajiparently not decomposed even at so high a tem- 

 perature as 275°, but between 2G0° and 275° it sublimes, giving 

 beautiful white crystals in the upper part of the tube. It is very 

 easily soluble in ether, benzol, alcohol, chloroform, acetone, ligroine, 

 glacial acetic acid, carbonic disulphide, acetic anhydride, or methyl 

 alcohol, but is insoluble in water. Ligroine is the best solvent for it. 



It is saponified by sulphuric acid of specific gravity 1.44, giving 

 the dichlordiethoxyquiuone melting at 104°-105°, and also a small 

 quantity of chloranilic acid. In the cold the acid produces little or 

 no effect on the acetal, but after warming on the steam bath for half 

 an hour the saponification is complete. A more dilute acid seems to 

 have no action upon it. Sodic hydrate, even when boiling or mixed 

 with alcohol, does not decompose the acetal. 



The differences between the properties of the tetraetliylacetal and 

 the diethyllieraiacetal certainly are remarkable. The hemiacetal is 

 entirely insoluble, while the acetal is exceedingly soluble in all the 

 common solvents except water. The former is very unstable, being 

 readily decomposed by even very dilute acids, while the latter is sa- 

 ponified only slowly by comparatively strong acids when heated with 

 them. By heat also the hemiacetal is easily decomposed, whereas 

 the acetal sublimes apparently unaltered at high temperatures. 



The action of bromine on the tetraetliylacetal might prove of great 

 interest, as the formation of addition products from it similar to those 



