148 REPORT — 1860. 



is evaporated in a current of hydrogen or coal-gas, and the crystals much resemble 

 those of hsematoidine. The hsematoidine extracted by Valentiner and Briicke 

 from gall-stones and ox-bile has some resemblance to this new acid. From the 

 above reaction it is evident that cholochrome, like the other acids of the bile and like 

 hippuric acid, leucine and tyrosine, and many other substances connected with the 

 human economy in health and disease, is an amido-acicl, i. e. an acid in which the 

 nitrogen is contained in the form of amide (NH 2 ) ; this radical replacing one equi- 

 valent of hydrogen in the hypothetical acid, of which the cholochromic is the oxy- 

 a?id, the radical (N IP) in the amido-acid being replaced by peroxide of hydrogen 

 (HO 2 ) in the oxyacid. 



With nitric acid, cholochrome yields an amorphous yellow substance, little 

 soluble in water, nitro-cholochrome, a crystallizable acid easily soluble in alcohol, 

 perhaps nitrocholic acid ; and a colourless syrupy acid easily soluble in water, and 

 yielding a crystallized salt with ammonia, perhaps cholesteric acid or ahomologue. 

 Chlorine transforms the brown matter, cholophaine, into the green cholochloine in 

 the space of a few minutes. The pi'ocess of Ileintz required several weeks for 

 effecting the same transformation. The continued influence of chlorine produces 

 the red cholochromic acid, which exists, however, only for a moment, being trans- 

 formed into white chlorocholic acid, little soluble in water, more soluble in alcohol. 



These researches have been undertaken by Dr. Thudichum, partly with a view 

 of ascertaining the pathological process which gives rise to certain casts of the 

 biliary ducts, previously described by him in the ' British Medical Journal.' He 

 believes it to resemble the putrefaction of bile in a stoppered bottle. If the process 

 is acute, it constitutes "biliosity or biliousness;" if more chronic, it gives rise to 

 casts of the ducts and gall-stones ; if it extend to the liver-cells, it constitutes ma- 

 lignant jaundice. 



The author further intimates that, since the above reaction with nitrous acid is 

 now ascertained, the therapeutic effects of nitric and nitro-hydrochloric acids in 

 various forms of jaundice, which are already recognized hy many practitioners, are 

 deserving of further investigation and trial. His own experience is in favour of 

 these remedies. 



GEOGRAPHY AND ETHNOLOGY. 



Opening Address by the President, Sir Roderick Impey Murchison, 

 D.C.L., F.R.S., V.P.R.G.S. % V.P.R.G.S., Director- General of the 

 Geological Survey of the United Kingdom. 



During the last two years only, the President of each Section of the British Asso- 

 ciation having usually opened the business of the Meeting by a short address, it fell 

 to my lot to offer a few words to the Geographers and Ethnologists who were as- 

 sembled at Leeds in 1858. I there expressed the satisfaction I felt in proposing, at 

 the Edinburgh Meeting in 1850, the formation of a separate Section for Geography 

 and Ethnology, to occupy the place left vacant by our Medical Associates who had 

 seceded to found an Association of their own. 



Until that year Geography had been attached exclusively to the Geological Section, 

 in which it was almost submerged by the numerous memoirs of my brethren of the 

 rocks, whilst Ethnology, forming a Sub-Section, with difficulty obtained a proper 

 place of meeting. Now, however, both these sciences are, [ am happy to say, fully 

 represented, and I trust that the result of the coming week will show that the sub- 

 jects to be illustrated will attract so many members to our hall, as will prove that 

 Geography in its comprehensive sense is as popular in Oxford as it is in the metro- 

 polis. 



Before I enter upon the consideration of any memoirs which may be laid before 

 us, let me allude to a few of the subjects of deep interest which have been illustrated 

 by British Geographers in various parts of the world in the two years which have 

 elapsed since I had the honour of last presiding over you. 



In Africa, the earlier discoveries of that great traveller Livingstone have been fol- 



