ELISHA MrTCHELL"]JSClENTIFIC SOCIETY. 43 



The b.ises differ as to melting point and solubility and are clearly 

 isomeric. We have in this fact an intimation, at least, if nothing 

 more, that to our base is to be assigned the formula (a) and not (b) : 



(a) r;H,(l)gj^=_C CH,.CH3 (b) CH3(1) |^]g^~C.CH,.CH, 



This conclusion is reached by regarding the group -NH- positive, 

 and =C= negative; this granted, we should expect, bearing in mind 

 the principles given on page 41, that (a) would give, upon broma- 

 tion : 



CH., (1) {|^jj;iC.CH,.CH3, Br (6) or CH3 (1) [|'^jj=C.CH,. 



CH3, Br (4), (most probably the first). 



Either would explain the isomerism; (b), on the contrary, would 

 give 



CH3 (1) [gj^^^CCH,. CH3,Br (5) 



which is the formula assigned to base No, 1, and is, therefore, not 

 admissible. We therefore conclude that not (b) but (a) represents 

 the constitution of our base. But the point cannot be regarded as 

 settled by these considerations. Whether there exists in fact as in 

 theory a difference such as indicated by (a) and (b) remains a ques- 

 tion. 



J. M. PICKEL. 



State Agricultural College, Lake City, Fla. 



EFFFXT OF FREEZING ON STANDARD SOLU 



TIONS. 



F. B. DANCY. 



I desire to call attention to apparent changes which were manifest 

 in standard acid and alkali solutions after being frozen in the cold 

 snap in January, 1886. 



The solutions were those used in determining nitrogen in nitro- 

 genous materials. One was a solution of sulphuric acid one-fourth 

 normal (0.02 gramme SO3 in each c. c.) and the other was a solution 

 of potassium hydrate of such a strength that one c c. of the pot- 



