Septembek 29, 1905.] 



SCIENCE. 



409 



possible that in aqueous acids we have pres- 

 ent, not the ion H, but OH3 or OH, . H. In 

 each case the hydrogen ion would be associated 

 with a molecule of the solvent. Besides these 

 compounds which act as acids in water, there 

 are other compounds not acids in aqueous 

 solution, which act as acids in ammonia. 

 Such, for example, are the acid amids and 

 imids. In acetamid we may, perhaps, assume 

 the ions CHjCONH and H ; in urea the ions 

 H,NCONH and H, as well as CO(NH), and 

 211. Here the NH seems to play the same 

 part as the oxygen atom of the hydroxyl of 

 acetic or earbamic acid. When sodium is dis- 

 solved in liquid ammonia, it gradually decom- 

 poses it with the evolution of hydrogen and 

 the formation of sodium amid, NaNH,. The 

 reaction is of coiirse exactly analogous to the 

 action of sodium on water with the formation 

 of sodium hydroxid, NaOH. The interesting 

 point is that sodium amid in ammonia solu- 

 tion is a base, just as sodium hydroxid in 

 water. It colors phenolphthalein and neutral- 

 izes the ammonia acids. Just as aqueous 

 bases contain the OH ion, the ammonia bases 

 contain the NH^ ion. When the bases react 

 upon acids in liquid ammonia, salts are 

 formed, which may be precipitated when in- 

 soluble, or left as crystals on evaporating the 

 ammonia. Thus the reaction between acet- 

 amid and potassium amid may be expressed as 

 follows : 



CH3CPNH . H 4- K . NH2 = CH3CONH . K -{- NH3. 

 Salts of the strongly positive metals, as far 

 as they are soluble, dissolve in ammonia as in 

 water without change. Compounds of the 

 negative elements are more or less completely 

 hydrolyzed by water. The same compounds 

 are ' ammonolyzed ' by liquid ammonia. The 

 analogy is shown by comparing the reactions: 



ASCI3 -f 3H . OH = As ( OH ) 3 + 3HC1 

 AsCla 4- 3H . NH2 = As (NH2) 3 + 3HC1, 



{3HC1 + 3NH3 = 3NH,C1) . 



As the hydrolysis of SnCl^ gives us not 

 Sn(OH)^ but SnOCOH),, so the ammonolysis 

 of PCI3 gives not P(NH,)3 but P(NH)NH„ 

 and of 8182 gives Si(NH), rather than 

 Si(]S[H.,)4. As with hydrolysis so in am- 

 monolysis the reaction need not go to com- 



pletion. In such a case we have in aqueous 

 solution the precipitation of basic salts, and 

 so here also are formed ammono-basic salts, 

 which may be more or less de-ammoniated anji 

 hence appear as amins, imins or even as. 

 nitrils, that is, nitrids. The reaction of the 

 formation of these basic salts is, as would be 

 expected, reversible, and they can, after pre- 

 cipitation, be carried back into solution by 

 an excess of ' ammono-acid,' that is, by an 

 ammonimn salt. ■ This method of treatment 

 seems to clear up very satisfactorily the mer- 

 cury-ammonia compounds which have for 

 nearly three quarters of a century been a 

 stumbling block to chemists. They here ap- 

 pear to be ammono-basic salts, or mixed 

 hydro- and ammono-basic salts, occasionally 

 with ammonia of crystallization. They thus 

 fall completely in line with the many and 

 more familiar hydro-basic compounds of mer- 

 cury. 



It is a large field which has thus been opened 

 by Franklin, and one which will require ranch 

 work, of great experimental difficulty, before 

 it is satisfactorily worked over, but what has 

 been already done has served to greatly 

 broaden our knowledge of solutions. 



J. L. H. 



FIK.^T INTERNATIONAL CONGRESS OF 

 ANATOMISTS."- 



The first meeting of the Congres federatif 

 international d'Anatomie was held in Geneva, 

 and commenced on the morning of Sunday, 

 August 6, by the opening of an exhibition of 

 specimens and appliances illustrating recent 

 progress in anatomy. The congress closed on 

 the evening of Thursday, August 10, when 

 three hundred members and adherents of the 

 congress were entertained by the city of 

 Geneva at an official banquet. The congress 

 represented a conjoint meeting of the five 

 leading anatomical societies — the Anatomical 

 Society of Great Britain and Ireland, 

 Anatomische Gesellschaft, Association des 

 Anatomistes, Association of American Anat- 

 omists and the Unione Zooligica Italiana. 



^ From Nature. 



