Quarterly Report of the Chemical Committee for Decemher. 287 



land. Weakness in straw is generally ascribed to a deficiency of 

 soluble silica in the soil ; but whilst this may be the case in 

 exceptional cases, it is well to be reminded that there is not 

 a single experiment on record which shows positively that the 

 direct application of soluble silica has ever had a decidedly bene- 

 ficial effect upon corn crops. 



It is further an unquestionable fact that there are few soils 

 which do not contain an abundance of soluble silica. The weak- 

 ness in straw in most cases arises not so much from the want of 

 silica as from the deficiency in the soil of available potash, phos- 

 phoric acid, lime, or some one or more equally necessary mineral 

 food constituent ; and, not unfrequently, weakness in the straw of 

 corn-crops is the result of a general abnormal and unhealthy 

 growth, induced by too copious an application of nitrogenous 

 manures. 



I cannot, therefore, help regarding iron-slag as mainly useful as 

 a good and cheap form in which lime can be used in agriculture. 



Summary of Analyses made for Members of the Boyal Agricultural 

 Society, from 1st Decemher, 1872, to 1st December, 1873. 



Guanos 38 



Superphospliates, dissolved bones, and similar arti-) 0-19 



ficial manures ) 



Bone-dust 27 



Nitrate of soda and sulphate of ammonia 32 



Potash-salts 5 



Kef use manures 36 



Limestones, ironstones, and other minerals .. .. 16 



Soils 27 



Waters 50 



Milk and whey 6 



Oilcakes 181 



Feeding meals 19 



Vegetable productions 11 ' 



Examinations for poisons 10 



Total 670 



XII. — Quarterly Report of the Chemical Committee for December, 

 1873, and subsequent Correspondence relating thereto. 



The Committee have to report that in two instances parcels of 

 linseed-cake, sold as " pure " by two members of the Hull Pure 

 Linseed-cake Association to two members of the Society, having 

 been found on analysis by Dr. Voelcker to be of inferior quality, 

 they instructed the Secretary of the Society to communicate with 

 the Chairman or Secretary of that Association. 



