Proceedings of the British Association. 55 



crystals : while the mother liquid is preserved, and yields a large 

 quantity of parabanic acid, or oxalurate of ammonia. By this 

 process the author obtains from 100 parts of uric acid, 65 of an- 

 hydrous alloxan, or 90 of alloxan + 6 aq. From alloxan, allox- 

 antine is easily obtained by the action of sulphuretted hydrogen. 

 Thionurate of ammonia is easily formed, by boiling a solution of 

 alloxan with sulphite of ammonia, and free ammonia. Uramile 

 is also easily obtained, by boiling a solution of thionurate of am- 

 monia, with an excess of dilute sulphuric acid. Murexide is ob- 

 tained, as has been already described, (p. 46 of this No.) The 

 theory of the formation of murexide is of great importance in ref- 

 erence to organic coloring matters. 



Sect. C. Geology and Physical Geography. 



Dr. Robb presented a communication on the geology of the 

 country around the River St. John, in New Brunswick. The 

 St. John is as large as any river of the first class in Europe. It 

 drains a large portion of the province of New Brunswick, and 

 the volume of water which it discharges into the Bay of Fundy 

 is very great, especially during the spring floods. Yet in one 

 place the river is so contracted that it is not more than 310 feet 

 in width. In the Bay of Fundy, as is well known, the tides rise 

 higher than in almost any other part of the globe, there being 

 sometimes, in spring tides, a rise of from 40 to 60 feet. The 

 tidal wave is then forced up into the narrow parts of the river, 

 and causes a backward fall of water, against the natural current, 

 of many feet in height. Dr. R. alluded to the singular configu- 

 ration of the country in the vicinity of the river, it being shaped 

 in terraces, one below the other. The river, from the distance, 

 between the first or uppermost pair of terraces, appears to have 

 been of much greater width, and subsequently to have grad- 

 ually become contracted, until confined within its present narrow 

 limits. The higher terraces slope towards the stream, the lower 

 ones become more horizontal, and the lowest is with a slope 

 turned from the river ; an appearance which Dr. R. explained 

 by the successive depositions of alluvial matter near the bed of 

 the stream, and extending no farther, so that depressions resulted 

 behind these depositions, which often contain water. In no 

 part of the world can the phenomena of rivers be studied better 

 than in America, from the little alteration produced upon them 



