( ±54 ) 
piperazino N{di) acetamide by applying- Hofmann’s original method or 
the modified process and therefore chose another way, namely, the 
reduction of the corresponding nitrile with sodium and alcohol. This 
nitrile was still unknown, although we were acquainted with the 
co-related amide the dicarbamino-piperazine or piperazino N v di 
carbonylamide (piperazyldi-urea) and the esters of the correlated acid 
dicarboxyalky 1-piperazine (piperazyldiurethane). The sought nitrile is 
N(di) cyanopiperagine or piperazino N{di) formonitnle. It was prepared 
from bromoeyanogen and piperazine in aqueous solution with addition 
of alkali. It is sparingly soluble in eold water, but more readily so 
than its homologue, and insoluble in ether. It crystallises from alcohol 
in leaflets m.p. 168°, which shine like mother of pearl; from water 
it is deposited in long flat crystals with a strong lustre resembling 
in form the well known Gypsum troins. This nitrile, like its homologue 
gives, in benzene solution, a white hygroscopic precipitate with dry 
hydrogen chloride, which is no doubt a combination with HC1. 
It does not combine with methyl iodide and (unlike its homologue) 
not with benzene either. In water, no compound is formed with 
oxalic acid. 
By reduction of this nitrile with sodium and alcohol we have 
obtained the desired amine, which crystallises beautifully with water. 
The compounds with hydrogen chloride, picric acid and oxalic acid 
have been prepared, and also the picryl and benzoyl derivative and 
will be described later on in the “Recueil des Traveaux chimiques.” 
We may state here, however, that the amine is not decomposed 
on boiling with dilute sulphuric acid; in any case it does not yield 
ainrhonia and formaldehyde as might have been expected from a 
derivative of methylenediamine (which it certainly is). 
Physics. — “ Some remarks suggested by a paper by Messrs. 
Timmermans and Kohnstamm.” By Mr. J. J. van Laar. (Com¬ 
municated by Prof. H. A. Lorentz.) 
In these Proceedings Voi. XII, p. 234 in a paper by Messrs. 
Timmermans and Kohnstamm some remarks occur in reference to 
my former papers on plaitpoint lines etc., which remarks, in my 
opinion, rest on a misunderstanding. 
I hope later on to collect the papers published by me on the 
subject mentioned in a book, but I may be allowed already now 
briefly to refute Messrs. T. and K.’s ideas concerning the results 
obtained by me theoretically. 
