Dr. J". E. Reynolds on a New Group of [Apr. 20, 



tained that the solution of mercuric oxide under the conditions mentioned 

 depended wholly on the presence of acetone in the crude wood- spirit ; 

 since pure acetone, when treated in the same way with diluted alkali and 

 mercuric oxide, afforded the same result, while the remaining constituents 

 of wood-naphtha failed to produce the reaction. 



Though obliged at the time to rest content with recording * the obser- 

 vations above referred to, I have since been able to resume the inquiry. 

 As the result, I now venture to lay before the Society the following account 

 of some members of a series of ketone compounds containing mercury, and 

 presenting all the characters of strongly marked colloid bodies, though 

 chemically intermediate .between the two groups of colloids previously 

 made known by the researches of the late Professor Graham. 



Acetone, being the most important member of the fatty ketone group, 

 is the body whose compound with mercury I have studied with chief atten- 

 tion, and I may therefore describe in detail the results obtained with it. 



1. Colloid body obtained by uniting Acetone with Mercuric Oxide. — 

 When solution of mercuric chloride is slowly added to a mixture of acetone 

 with dilute aqueous solution of potassium hydrate, the mercuric oxide first 

 precipitated is dissolved, with the production of a clear colourless liquid. 

 The addition of the mercurial solution can be continued until a white pre- 

 cipitate makes its appearance, the alkali being still in excess f. If the 

 solution be filtered at this point, an apparently opalescent, yellowish- 

 coloured liquid is obtained %. If one portion of this alkaline solution be 

 boiled for a few minutes, a thick gelatinous mass suddenly separates, and 

 further ebullition is rendered difficult, if not impossible. Another portion 

 of the liquid, when treated with an acid in slight excess, gelatinizes ; and if 

 the original solution be moderately strong, the vessel in which the experi- 

 ment is made may be inverted without risk of spilling its contents. 

 Finally, if some of the mercuric solution be exposed over sulphuric acid 

 in vacuo, it leaves on partial evaporation a gelatinous mass, on the surface 

 of which latter crystals of potassium chloride soon make their appearance. 

 When the desiccation is complete, a yellowish resinoid body is obtained, 

 together with a large quantity of very beautiful acicular crystals of the 

 chloride and a certain amount of potassic carbonate. 



The solution of mercuric oxide in potassium hydrate in presence of 

 acetone takes place as easily in alcoholic as in aqueous liquids. 



Preliminary experiments similar to the foregoing were sufficient to in- 



* Journal of the Koyal Dublin Society, vol. iv. p. 114. 



t The same result can be obtained when mercuric oxide is precipitated from any of 

 its salts, rapidly washed, and then digested with excess of acetone and potassium 

 hydrate. The best mode of operating, however, is that stated in the text. 



\ The different solutions exhibit a slight opalescence, not completely removable by 

 ordinary nitration. Tbis opalescence appears to be due to the very gradual separation, 

 at ordinary temperatures, of traces of the same anhydrous substance which is very 

 rapidly thrown down at a boiling heat. In composition the latter body is identical 

 with the anhydride obtained by other methods and described further on. 



