179 



On the Ultimate Analysis of Vegetable and Animal Substances. By 

 Andrew Ure, M.D. F.R.S. Read June 27, 1822. [Phil. Trans. 

 1822, ;>. 457.] 



Dr. Ure commences this paper by adverting to the fallacies to 

 which the modes of analysing organic substances hitherto practised 

 are subject; and in detailing the peculiar methods adopted in his own 

 researches, he shows the means of obviating them, and of diminishing 

 the various sources of inaccuracy to which these complicated pro- 

 cesses of analytical chemistry are necessarily more or less liable. 

 Where oxide of copper is used, its hygrometric quality has generally 

 been overlooked, or not duly allowed for; and the animal and vege- 

 table substances have not in general been exposed to any process of 

 desiccation sufficiently exact or uniform ; the author therefore always 

 used the oxide of copper in some known or ascertained degree of 

 humidity ; and he dried the organic bodies in the air-pump vacuum, 

 aided by the absorbent powers of a surface of sulphuric acid in the 

 apparatus, and with precautions which he fully describes. He then 

 details the best means of applying heat for the decomposition of or- 

 ganic substances, and describes a drawing representing the construc- 

 tion of his furnace, and other implements. Lastly, he points out the 

 method of examining the results and products, and gives in detail 

 the analysis of sulphuric ether, as illustrating the mode of computing 

 the relations of the constituents, while the results of the other ana- 

 lyses are, for the sake of brevity, thrown into a tabular form. Dr. 

 Ure concludes his paper with some general remarks on the analy- 

 tical details. In respect to sugar, he observes, that on comparing 

 pure crystalline sugar with diabetic sugar, the latter exhibits a no- 

 table excess of oxygen ; and he considers weak sugars (as the re- 

 finers call them), in general, to exhibit the same peculiarity. 



In applying the atomic theory to his experimental results, the 

 author enlarges on the different views which may be taken of the 

 ultimate constitution of a variety of organic products, and enters 

 at considerable length into details relating to the vegetable acids, 

 with a view of determining with exactness their prime equivalents, 

 and the relative proportions of combined water which they contain 

 in their crystalline states. 



The Croonian Lecture. Microscopical Observations on the Suspension 

 of the Muscular Motions of the Vibrio tritici. By Francis Bauer, 

 Esq. F.R.S. F.L.S. and H.S. Read December 5, 1822. [7V//7. 

 Trans. 1823, p. 1.] 



The Vibrio tritici is a small worm which infects wheat, being the 

 immediate cause of that destructive disease called Ear Cockle, or 

 Purples. Upon examining the grains thus diseased, the author found 

 them to be the unimpregnated germens, containing masses of a white 

 and apparently gluey mucus, which might be removed in the shape 

 of a firm ball, and which, when immersed in water, and viewed 



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