TRANSACTIONS OF THE SECTIONS. '71 



vatives of ammonia has of late been studied with considerahle care, and most in- 

 teresting results arrived at in the course of the investigation. We have been long 

 familiar with the reactions of aldehyde with aniline, described by Schiftj who has 

 shown that the dyad group, 0,11^", or ethyliden, as it is often called, can replace 

 successivelj' two distinct proportions of hydrogen in the double molecule of ani- 

 line, water being eliminated according to the equations : — 



2(C„H„NH,)-FaH,"0= jg^g^'jjg^^^l -1-11,0 (1) 



2(C„H3,NHJ-F2(C,H;'0)= ]g^g^gg^g^;;|+2H,0 (2) 



We are also acquainted with analogous reactions which have been obtained with 

 amides and aldehydes of the aromatic series ; it therefore appeared to be a matter 

 of some interest to examine the action of aldehyde on another class of ammonia de- 

 rivatives, the group of so-called ureas. Of these, there are at least two primary 

 bodies — one the well-known product of the animal organism, or Wohler's beau- 

 tiful artificial m-ea ; and the other, the sulpho-urea, which was discovered a few 

 years ago by the author. 



It is unnecessary now to discuss the question of the identity or otherwise of 

 Wohler's and the normal urea ; it is sufficient here to mention that all these experi- 

 inents have been made on Wohler's urea and on the analogous sulphur compound. 



It will be convenient for the present to regard the two ureas just referred to as 

 ammonia derivatives respectively of cai'bonic (according to Dr. Kolbe carbamic) 

 and sulpho-carbonic acids ; thus — 



Wohler's urea ^^"{nH^' 



Sulpho-urea ^^"{nh'' 



the author's object being to attempt the partial or complete replacement of 

 hydrogen in each urea by the ethyliden group, according to the equation 



cs{5Jg^}+c,H,"o=cs{NC.H;'|_^jj,o. 



The chief results arrived at in the course of the inquiry are the following :— 



Action of Aldehyde on the SidpJio- Urea. 

 The first experiments were made with the sulpho-urea. A quantity of the pure 

 compound was dissolved to saturation in nearly anhydrous aldehyde. The hot 

 saturated solution was digested in a hermetically sealed flask, at a temperature of 

 100° C, for two hours. The solution was then allowed to cool. No urea-crystals 

 were deposited. After two days' standing, however, a number of minute, spheri- 

 cal, subcrystalline masses were found to have attached themselves to the sides of 

 the flask, and these gi-adually increased in quantity, until a considerable amount 

 had been obtained. The clear liquid gave a copious white precipitate with water 

 and with alcohol. The deposited body was carefully washed with cold alcohol, 

 in which it is very slightly soluble, and then purified by solution in a large vo- 

 lume of boiling anhydrous alcohol, from which the new body separates out to a 

 large extent on cooling, as a somewhat starch-like gi-anular substance, seen under 

 the microscope to be made up of extremely minute crystals. The analysis of the 

 body gave numbers agreeing well with the formula 



and is therefore derived from the urea by the replacement of half the hydrogen 

 by ethjdiden. 

 ' The new body is but slightly soluble in ether, rather more so in cold alcohol, 

 but its solubility in boihng alcohol is much greater. In consequence of its rela- 

 tions to these solvents, the substance can be easily purified. It is but very slio-htly, 



