90 T. S. Hunt on Chemical Classificatio?is. 



close correspondence between the two classes of compounds ; the 

 law of their basicity is known to be the same as that of the ethers. 

 The monobasic amid acids correspond to bibasic non-azotized 

 ones, the bi-amids of which are neutral. The suggestion which 

 M. Gerhardt with his usual profound sagacity advanced several 

 years since, that all the azotized acids (the nitric ones excepted) 

 were acid amids, is strongly supported by late researches.* 



Ammonia like the alcohols, has the power of exchanging the 

 whole or a part of its hydrogen for a metal, as in Kane's amidids 

 of mercury, and such compounds as NK 3 and NHg 3 , and we 

 might therefore expect to find the amids occasionally exhibiting 

 saline properties due to this; accordingly, Laurent has found that 

 asparagine is capable of exchanging one equivalent of hydrogen 

 for potassium, and Piria has described crystalline compounds with 

 silver and copper of analogous constitution. Asparagine is the 

 binamid of the bibasic malic acid, and should therefore in accord- 

 ance with the general rule be neutral, while it is in truth mono- 

 basic ; at the same time its acid characters are but feebly devel- 

 oped, when compared with proper acid-amids as the aspartic and 

 oxamic acids, for the reason that they are only those belonging to 

 ammonia. Certain anhydrid amids exhibit the same tendency to 

 exchange their hydrogen for a metal, e. g., paramide, and prussic 

 acid, which is the formic anhydrid amid. The anilids and 

 naphthalamids, as far as examined, appear to be subject to the 

 same laws as the amids. 



Acids with Carbohydrogens. — The stronger mineral acids only, 

 form combinations with these bodies; the sulphuric generally 

 yields with one equivalent, a monobasic acid, in which an equiv- 

 alent of its hydrogen is replaced by the elements of the hydro- 

 carbon — HO, and a neutral body with two equivalents, e. g., 

 benzene and naphthalene. These compounds, as M. Gerhardt 

 has observed, are analogous to sulpho-methyiic acid and sulpho- 

 methol. 



Sulphomethy late, S (H (CH 3 ) )0 4 



Sulphomethol. S(CH,) 4 



Sulphobenzite, S(H(C B H, - 0))0 4 



Sulphobenzid, S(C 6 H 5 - 0) a 4 



The products which nitric acid forms with an equivalent of 

 these bodies throw much light upon the constitution of these 

 and allied compounds; the first result of the action is generally 

 the formation of a neutral compound analogous in composition to 

 the sulpho-acids just mentioned. Benzene (C 6 H 6 ) yields nitro- 

 benzid (C 8 H 5 N0 2 ), which corresponds to nitric acid in which 

 C 6 H 5 - O replaces~H, thus N(C 5 H 5 -0)0 3 . These analogues 

 of the ethers sometimes regenerate the acid and organic substance 



See Piria on Asparagine, Am. Journal for Nov., 1848. 



