120 



Proceedings of the British Association. 



authors verified it by subsequent experiments on artificial arrange- 

 ments. The analysis of coal by dry distillation gave — 



Coke, 



Tar, 



Water, 



Light carb. hydrogen, 

 Carbonic oxide, ... 

 Carbonic acid, . . . 

 Olefiant gas, 

 Sulphuretted hydrogen 

 Hydrogen, 

 Ammonia, 



Nitrogen, 



Condensed hydro-carbon, 



. 68-92 

 . 12-23 

 . 7-61 

 . 7-04 

 . 113 

 . 1-07 

 . 0-75 

 0-75 

 . 0-50 

 . 0-17 

 . 0-03 



. oo-o 



100-00 



In the second part of the Report the practical application will be 

 detailed. 



1 On Malacca Guano/ by Dr. Canter. — This communication des- 

 cribed a peculiar substance, of which recently samples have been sent 

 to England. It was stated to be inferior to both the African and the 

 Peruvian, and curiously enough to consist almost entirely of the legs 

 and other indigestible parts of beetles. 



Mr. Pearsall made some observations ' On Masses of Salt disco- 

 vered in the lowest portions of Guano on the Island of Ichaboe.' — 

 The salt was transparent and colourless, very soluble in water, and 

 contained phosphoric acid, soda and ammonia, and a trace of some 

 organic matter, which became carbonaceous at a high temperature. 

 The salt, therefore, appears to be a microcosmic salt, phosphate of 

 soda, and ammonia. 



Friday. 



Prof. Daubeny 'On the Chemical Principles involved in the 

 Rotation of Crops/ — Prof. Daubeny made some remarks on the 

 chemical principles involved in the rotation of crops, stating the con- 

 clusions which he had deduced from a series of experiments carried 

 on within the Botanic Garden at Oxford, and intended to ascertain 

 the rate of diminution in the produce of several plots of ground that 

 had been sown for ten years, either continuously with the same, or 

 successively with different crops, in either case without the addition 



