hydrate to their saturated aqueous solutions, and are not decomposed even by long boiling with it. With iodine it unites to form tetramethylammonic pentaiodide, N(CH3),Is, which crystallises in brilliant metallic black crystals. Tetramethylammonic hydrate, prepared from the iodide by action of freshly precipitated argentic oxide, is crystalline, very deliquescent, and eagerly absorbs carbonic anhydride from the air. The nitrate N(CH3)4.O.NO, crystallises in long brilliant prisms. The chloride N(CH3),Cl gives with platinic chloride a double salt crystallising in orange yellow octahedra, [N(CH3),]2PtCl On strong heating tetramethylammonic hydrate splits up into trimethylamine and methylic alcohol: N(CH3),.OH= N(CH3)3 + CH3.OH. 274. Tetrethylammonic iodide, N(C2H),I, is readily soluble in water and alcohol. With alcoholic solution of iodine it yields bluish black crystals of azure blue lustre of tetrethylammonic triiodide, N(C2H),I3, which melt at 142°. Tetrethylammonic hydrate crystallises in vacuo in hairlike crystals, which are very deliquescent. On heating to 100° decomposition occurs, and there is obtained triethylamine and not alcohol, but ethylene and water: C2H5 6 The platino-chloride [N(C2H5)]2PtCl crystallises in regular octahedra. 275. The following bodies have also been obtained: Trimethyl-ethylammonic iodide, N(CH3)3(C2H5)I, from trimethylamine and ethylic iodide. Methyl-diethyl-amylic iodide, N(CH3)(C2H5)2(C,H11)I, from methyl-diethylamine and isoamylic iodide, and methyl-diethyl-isoamylammonic hydrate, which on heating yields ethyl-methyl-isoamylamine, water, and ethylene : N(CH3)(C2H)2(C,H11).OH = H2O + C2H, There have further been obtained: Triethyl-isoamylammonic hydrate from its iodide, and also tetrisoamylammonic hydrate. HYDRAZINE COMPOUNDS. 275a. This name has been given to a class of bodies containing the nitrogen group = N-N, whose free affinities may be satu rated either with hydrogen or alcohol radicals. They may be considered as derived from the nitro-hydride H,N-NH2, which has not yet, however, been isolated, by the substitution of its hydrogen by other groups. Primary hydrazines result by the substitution of one hydrogen There are two isomeric atom, and secondary by two of the latter. forms, the symmetrically substituted and the unsymmetrically sub stituted group. The relationship of the hydrazine series to the amines will be seen from the following list: These bodies may be obtained in the fatty series from the corresponding nitroso-ureas. This body is best prepared from diethyl or ethyl-phenyl urea, which is converted into a nitroso compound by the action of nitrous acid, and this reduced by zinc and acetic acid, the hydrazine urea being then decomposed by some strong acid into ethylhydrazine, carbonic acid, and ethylamine, or aniline. A good process is to dissolve 50 grms. of diethyl urea in 200 cc. water, acidified with 35 grms. of sulphuric acid, and then to add to the cooled mixture the calculated quantity of sodic nitrite in small portions. The yield should be about 30 grms., which is dissolved in 180 cc. alcohol, 120 grms. zinc dust and 60 to 70 grms. glacial acetic acid added, the whole being carefully cooled. When HCl ceases to produce a precipitate of nitrosamine the liquid may be separated from the zinc dust and treated with very concentrated sodic hydrate solution, shaken out with ether, and this solution, after being acidified with HCl, evaporated. The syrupy residue, consisting of the chlor-hydrates of diethyl carbamide and diethyl semi-carbazide, is boiled with three or four times its volume of fuming HCl, and finally saturated with HCl gas, whereby ethylhydrazine hydrochloride separates in needles. The base is obtained in a free state by distilling the last mentioned body with potash or baric hydrate. It is a mobile colourless liquid of ethereal odour, something like ammonia, boiling at 99-5° at 709 mm. pressure. It is soluble in water and alcohol, and very hygroscopic, and acts corrosively on cork and caoutchouc. It is very easily oxidised, and reduces alkaline copper solutions as well as silver and mercury salts in the cold. In the case of the latter metal a considerable quantity of mercury ethyl is produced. Bromine decomposes it immediately even in strongly acid solutions, liberating nitrogen. Its solutions behave towards most metallic salts like ammonia. It gives two classes of salts. The acid hydrochlorate, C2H5.N2H3.2HCl, forms fine white needles, soluble in water and alcohol with decomposition into the neutral salt, C2H ̧.N2H ̧.HCl, which remains on evaporation as a colourless, heavy, deliquescent mass. 2 Secondary Hydrazines. The unsymmetrical hydrazines of the fatty series are produced almost quantitatively by the reduction of the nitrosamines by zinc dust and acetic acid, the symmetrical hydrazines by the reduction of the corresponding azo compounds. Both varieties are simultaneously produced by the action of alkyl haloids on the primary hydrazines. Diethylhydrazine, (C,H5),N.NH2, is obtained by the careful reduction of diethyl nitrosamine with zinc and acetic acid. After the termination of the reaction it is separated from the zirc; and the filtrate, after addition of excess of sodic hydrate, is distilled with steam, best from a copper vessel. The watery distillate, which contains hydrazine, ammonia, and diethylamine, is saturated with HCl and evaporated to remove as much ammonic chloride as possible. Hydrazine and diethylamine are separated from this filtrate on addition of potash as an oil. To separate the hydrazine the oily mixture is treated with cyanic acid, thus forming Diethylhydrazine urea, difficultly soluble in water and alcohol, and which may thus be easily purified. It is finally distilled with solid potash or baric hydrate, and obtained as a colourless liquid of ethereal ammoniacal odour, boiling at 96°-99° and soluble in most of the ordinary solvents. It is a monacid base, and gives salts easily soluble in water and most difficult to get crystallised. With ethyl iodide it forms triethylazonium iodide : (C2H5),NI-NH2, white needles easily soluble in water and alcohol, insoluble in ether. Tetrethyl tetrazon, (C2H5),N.NN.N.(C2H)2. By oxidising an aqueous solution of diethylhydrazine with yellow mercuric oxide this body is obtained as a colourless oil, of an odour somewhat like leeks. It does not solidify at 20°, and can only be distilled in a current of steam. On boiling with water it is totally decomposed. Many mixed fatty aromatic hydrazines are known, and will be described under aromatic bodies. Alkylic Cyanamides. 276. By action of cyanogen chloride on the amines, substances analogous to the cyanamides are obtained: CI.CN+2N(CnH2n+1)H2 = N(CnH2n+1)H3Cl as also by desulphurising the mono-alcoholic sulphureas (§ 287) by mercuric oxide in boiling aqueous or alcoholic solutions : N(CnH2n+1)H N(CnH2n+1)H T +HgO= HgS + H2O + CEN NH2 By evaporation of the liquid from which the mercuric sulphide has been filtered, they are obtained as neutral syrups, which, by repented solution and evaporation, are readily polymerised into the crystallisable and strongly basic melamine derivatives: 3CN2H(CnH2n+1)= C3N6H3(CnH2n+1)3′ These latter can combine with two molecules of hydrochloric acid, but these salts easily decompose, with separation of ammonic chloride, into the analogous ammelide derivatives: C3N6H3(CnH2n+1)3,2HCl + H2O = NH ̧Cl + C3N5.H2(CnH2n+1)30,HC1; and similarly by long boiling with excess of hydrochloric acid into trialcoholic isocyanurates: C3N6H3(CnH2n+1)3 + 3HCl + 3H20 = 3NH,CI +C3N3-(CnH2n+1)303. By these reactions the melamine from which these substitution products are derived is not expressed by the formula already given (§ 117): H2N- - C—N N-C-NH2 H2N—C—N but only by the isomeric expression: HN-C-N-H H-N C-NH HN C-N-H 277. The most thoroughly investigated body of this class is triethyl melamine. This forms strongly alkaline, readily soluble, colourless crystals, whose cold concentrated hydrochloric acid solution gives with platinic chloride a double salt: C3N6(C2H5)3H3,2HCl,PtCl1, in easily soluble, wavellite-like, crystalline masses. By long standing, or in shorter time by boiling its solution, triethyl melamine hydrochloride decomposes into ammonic chloride and triethyl ammelide hydrochloride: HN C-N.C2H5 HN C-N.C2H, CH.N CNH + 2HCl + H2O=NH,C1+C,H,.N CO,HCI H.N-C-N.C2H5 HN C-N.C2H5 from which triethyl ammelide can be obtained as a syrupy mass readily soluble in ether and giving with hydrochloric acid and platinic chloride the double salt [C3NH2(C2H3)30]22HCl,PtCl ̧. By long continued boiling with hydrochloric acid triethylic isocyanurate is obtained : HN=C-N.C2H5 O=C-N.C2H2 C2H,.N C-NH + 3HCl + 3H20= 3NH4Cl + C2H ̧.N C=O HN C-N.C2H5 5 O-C-N.C2HS If triethyl melamine be submitted to dry distillation, it splits into two compounds, of which the one remaining in the retort as an amorphous mass is by its composition a monethyl dicyan-diamide; the other, boiling at 190°, is diethyl cyanamide: C3N6(C2H5)3H3= (C2N2)<NH2 Monethyl dicyan-diamide. C3H1002 Diethyl cyanamide. The latter must be a derivative of true cyanogen, as on boiling with alkalies it yields diethylamine together with ammonia and a car bonate: CEN N(C2H5)2 + 2KOH + H2O = CO(OK), + NH3 + N(C2H3)2H. Isocyanides of the Alcohol Radicals, CEN-CnH2n+1 278. The iso- or pseudo-cyanides of the alcohol radicals are formed by the action of argentic cyanide upon the iodides of the alcohol radicals (§ 96): CEN-Ag + ICnH2n+1= AgI + CEN-CH2n+15 and by mixing chloroform with primary amines and an alcoholic solution of potassic hydrate : CHCl3 + N(CnH2n+1)H2 + 3KOH = 3KCl + 3H2O +CN-CnH2n+1° In smaller quantity they are also formed as bye-products in the preparation of the isomeric true alcoholic cyanides by dry distillation of potassic cyanide with potassic alcoholic sulphates. They are liquids difficultly soluble in water, of fearfully disagreeable odour and very poisonous properties. With argentic cyanide they unite to form crystalline bodies of the formula CN.CnH2n+1,CNAg, probably C=N-CnH2n+1 Ag-NEC from which they can be set free by heating with an aqueous solution of potassic cyanide : CEN-CnH2n+1 Ag-NEC K-CEN +K-CEN = = | | +C=N—CnH2n+1· Ag-NEC |