288 Proceedings of Metropolitan Societies. [ April, 
A contribution to physiological chemistry, on the vexed question of 
the colouring matter of urine, was communicated by Dr. Thudicum, who 
believes that he has isolated both the pigmentary and odorous princi- 
ples of this secretion. The former body he designates wrochrome, the 
latter, otto of urine. In the absence of any analysis of these bodies, 
and without an exact knowledge of the manner in which they are to be 
obtained, the question, “ What is the colouring matter of the renal 
secretion?” may be still considered open, unless, with Dr. Harley, we 
believe it to have been settled by Scherer. This distinguished chemist 
and physiologist succeeded in isolating a red matter, to which he gave 
the name of urohematin, since it presented a close analogy to the 
colouring matter of the blood, by containing an appreciable amount of 
iron. Scherer considered the body to result from this disorganization 
of the blood corpuscles, the waste of which was eliminated from the 
system in this form. This is an ingenious theory, and the question 
deserves further examination. Dr. Thudicum finds the merest trace of 
iron in his urochrome ; but we must wait fora more complete account 
of the author’s researches. 
The formation of new bodies, by the abstraction from other bodies 
of certain elements or molecules of elements, and substituting for these 
certain other elements or groups of elements, the resulting compounds 
having well-defined and characteristic individualities ; and further 
than this, the production of natural from artificial substances (like the 
formation of tartaric acid from dibromosuccinic, by Mr. Perkin), by 
successive substitutions, may rank among the greatest triumphs of 
human ingenuity. Perhaps the most prolific parent of artificial bases 
has been Dr. Hoffmann, whose skill in effecting the transformations is 
only equalled by the lucidity with which he explains them. 
Apropos to a paper on Acetanilide, by Mr. C. G. Williams, the 
Chemical Society recently heard from Dr. Hoffmann a short account 
of a series of new creations, obtained by. the action of chloroform on 
aniline, and of pentachloride of phosphorus ona mixture of aniline and 
acetanilide —the first of an infinite series of bodies which may be pro- 
duced by similar reactions on similarly-constituted substances. ‘The 
names of these new bodies, diphenyl-formyl-diamine, and diphenyl- 
acyl-diamine, show them to be of interest only to advanced chemists. 
New instances of conversion were brought forward at the same meet- 
ing, malic acid having been converted into malonic, and propionic 
acid into succinic, by Kolbe and by Muller. 
The question, “‘ What is the best form in which nitrogen and phos- 
phorus can be applied as manure to plants ?” has engaged the attention 
of many minds; but perhaps the most original experiments made on 
the subject, have been those of M. Ville, recently described to the 
Chemical Society by Dr. Hoffmann. M. Ville has, however, come to 
the conclusion that none of the compounds of phosphorus and nitrogen 
answer better than those in common use—phosphorice acid and ammonia. 
It will be of interest to farmers who study chemistry, to learn that 
ethylamine and methylamine seemed to produce no better results than 
their prototype ammonia. 
