TO CORRESPONDENTS

1831 The Lancet  
When a current of chlorine,gas is passed through bile, the liquid loses its colour and smell, passing successively from an azure i blue to dark-yellow, and, finally, to pale white : a white matter is then deposited. The bile thus altered is soluble in cold alcohol. The white substance is insoluble in that fluid, and may be collected on a filter ; it is soluble in ether, and contains the fatty matter of the bile altered by chlorine. The alcoholic solution, on evaporation, disengages vapours of
more » ... riatic acid, and deposits crystals of muriate of soda, and finally is reduced to a mass, which, when heated, is liquid like turpentine, but which hardens in the cold, and presents all the characters of a perfect resin, which may be perfectly freed from muriate of soda by washing with water. This resinous substance is of an obscure yellow colour, slightly bitter, solid and friable at ordinary temperature, becoming electric by friction, is remarkably soluble in alcohol and ether, slightly so in warm water, with which it forms a kind of emulsion. All these solutions redden litmus paper. The resin is decomposed by heat, giving rise to azotised products, in which respect it differs from common resins ; an empyreumatic oil, containing muriatic acid, is formed at the same time. It possesses some acid properties, combining with bases in solution, from which it is precipitated by acids in white flakes. It is not sensiblv altered by the nitric or muriatic acid, but is decomposed by the sulphuric acid, giving I rise to the formation of liquid of a beautiful I red colour. According to these characters, M. Matteucci conceives that this substance is identical with that found by M. Braconnet in the picromel of Tlienard, and he proposes to term it the chloro-bilic acid. This acid combines readily with the metallic oxides ; it forms with soda, potassm, lime, and ammonia, soluble compounds, from which this acid is precipitated by the smallest quantity of any other ; its combinations are always with an excess of base. The green and sweet matter of the bile is easily obtained, according to M. Matteucci, by leaving in contact, during tweire or fifteen days, a mixture of bile and sulpburic acid, previously agitated till the liquid assumes a yellow colour. At the end of this time the yellow substance (or the chloro-bilic acid) is deposited, and the liquid assumes a fine green odour. It is then decanted, neutralised by lime, boiled, filtered, aud evaporated, and the residuum constitutes the green principle. This sub-stance possesses a sweet flavour, analogaua to that of liquorice ; it is very soluble in water and alcohol, and its colour is entirely destroyed by chlorine.
doi:10.1016/s0140-6736(02)94048-1 fatcat:op5vgxnvxfc6lmjvnmnahta3hm