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quantity of the diazoniumcompound disazodyes are formed. It was 
also found that the diazonium radical may substitute as readily 
hydrogen atoms in the @ as in the f position of the pyrroline nuc- 
leus, and it was therefore highly probable that haemopyrroline, should 
it really represent a homoloque of pyrroline, will also yield azo- 
dyes. These expectations were fully born out by experiments. We 
found that an ethereal solution of haemopyrroline shaken with a hy- 
drochlorie acid solution of a diazonium compound turns quickly 
reddish brown and on standing of the ethereal solution, which had 
been separated from the aequous solution, for some time reddish 
brown needles are formed which could represent a monoazo or 
a disazocompound of haemopyrroline After this first experiment, 
carried out using only a comparatively small amount of haemo- 
pyrroline, we started experiments on a somewhat larger scale and 
found that the reaction between the product called haemopyrro- 
line, and diazoniumcompounds is indeed far more complicated than 
was at first supposed and that there are formed at least three sub- 
stances, of which up to now we succeeded in isolating in suffi- 
cient quantities only one. 
Haemopyrroline and Benzenediazoniumchloride. 
Haemopyrroline we obtained by reducing haemin with hydro- 
iodie acid in the presence of phosphonium iodide. The haemin was 
prepared according to Nenckis and Zaleskis method, the quantity 
reduced for each experiment amounted to 5 g of haemin which were 
dissolved in a mixture of 100 g glacial acetie acid and 100 g of 
hydroiodie acid and heated on a waterbath. To this solution were 
added gradually 8 g of phosphonium iodide. As soon as the redue- 
tion was completed the excess of acetic acid was neutralised by 
adding caustie soda and distilled in a current of carbon dioxide. 
As soon as samples of the destilate showed no reaction with mer- 
euric chloride we extracted the haemopyrroline with ether and 
treated the ethereal solution immediately with the diazoniumcom- 
pound obtained from 50 em? 1/; n. aniline chloride solution, con- 
taining 2 mol. of free hydrochlorie acid. The ethereal solution tur- 
ned at once reddish brown and the colour gradually became dark 
violetish-brown. After separating the ethereal solution from the acid 
liquor the former yielded after a short time yellowish erystals which 
however after a days standing in the cold were replaced by brown 
