"Proceedings of the British Association. 123 



useful as an illustration of that system of Scientific Book-keeping, 

 which he had proposed at a former meeting of the Association, at 

 once as an useful exercise to the agricultural student, and as a 

 means of introducing greater precision into the conduct of our experi- 

 ments in such subjects. 



' On the Ashes of Wheat,' by W. Sharp. — Mr. Sharp noticed that 

 the amount of the ashes of wheat was given from Sprengel as 1*177 

 per cent., whereas Sprengel himself (page 446, vol. 2, of his ' Chemie 

 fur Landwirthe,' &c,) states it to be 1*777; Dr. Daubeny, on the 

 other hand, gives Sprengel' s analysis as 2*137 ; — both on the sup- 

 position of a misprint in Sprengel' s book. This led Mr. Sharp to 

 undertake some experiments in order to ascertain the truth ; and one 

 suggestion arising out of another, about a hundred experiments were 

 performed, with great care, on varieties of red and white wheat, grown 

 on different soils and climates in England, Germany, Sweden, Poland, 

 Holland, and Saxony. Ultimately, answers to the following questions 

 were sought and apparently found : — 1st. What is the average 

 amount of inorganic matter in the grain of wheat ? From 1*5 to 1*75 

 per cent. — 2nd. What is the difference in the result obtained from 

 the combustion of wheat which has been previously dried at different 

 temperatures ? A great number of experiments were made by drying 

 at temperatures of 245°, 260°, and 60°, and the difference of re- 

 sults was shown to be considerable. — 3rd. Can any temperature be 

 recommended as the one to be preferred, at which the materials for 

 these and similar experiments should be dried ? The result of the 

 experiments alluded to in the previous answer was in favour of the 

 temparature of 60°. — 4th. Can any chemical preparation be added 

 to the substances experimented upon, before or during the combus- 

 tion, which will facilitate the otherwise tedious process ? Several sub- 

 stances were tried, particularly nitric acid, but they all failed to give 

 satisfactory results. The per-centage left by nitric acid was always 

 less, but not uniformly less, than it ought to have been. — 5th. Does 

 the quantity of inorganic matter bear any relative proportion to the 

 specific gravity of the grain, — that is, to its weight per bushel ? 

 The experiments show that a steady inverse ratio is maintained be- 

 tween the proportionate weight per bushel and the amount of ashes. 

 Wheat weighing 641b. per bushel yields 1*5 per cent.; and this 



