PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 389 



selected was yJ-^ of an acre, which, in the hands of Mr. R. J. 

 Thomson, formerly of Grange, Kilmarnock, had been found to 

 give excellent results, as can be testified by several members of 

 the Society who have had occasion to inspect his results. It will 

 be seen in the sequel that some precautions which he did not 

 find necessary, are required in particular cases. 



In fixing on the particular experiments to be made, the 

 Committee had a difficult duty to perform. A number of 

 valuable suggestions were made by different individuals of sub- 

 jects well meriting investigation. After considering these, it 

 was finally remitted to Mr. Goodlet, Bolshan, who has taken a 

 lively interest in all the arrangements, and myself, to draw up a 

 scheme of experiments, on the understanding that these should be 

 of a simple character, and should embrace those matters which 

 seemed most generally interesting. This, after having been 

 submitted to the practical members of the Committee for their 

 opinion, and having undergone some modifications, was finally 

 approved of. The exact principles on which these experiments 

 were based, will be more particularly explained, when the actual 

 results are given. 



The whole arrangements connected with the manures were 

 undertaken by myself, and carried out in the laboratory. The 

 substances used were all of the best quality that could be ob- 

 tained. When delivered, they were carefully sampled, a quan- 

 tity being taken from every bag, mixed with great care, and a 

 portion of this being taken for analysis. A duplicate determi- 

 nation of all the more important constituents was made so as to 

 avoid all risk of error, and from the results thus obtained, the 

 quantity of the manure to be employed for each plot was calcu- 

 lated in the manner to be afterwards explained. The manure 

 to be weighed was taken from each of the sacks, mixed so as to 

 insure uniformity— just as had been done in sampling — weighed, 

 and put into small canvass bags. Where two substances were 

 to be applied to the same plot, they were weighed off separately, 

 and then mixed in a large earthen basin by careful stirring and 

 turning over. When glue was one of the substances employed, 

 it was not mixed with the other, as it might have become damp, 

 and the whole have set into a solid mass, but was sent out in a 

 separate bag. A label of zinc, with distinctive numbers stamped 

 upon it, was attached by a piece of wire to -the mouth of each 

 bag, and these were found to answer the purpose perfectly, and 

 are infinitely preferable to paper or parchment, which are apt to 

 become illegible from moisture, or the acids contained in the 

 manures ; and it was the confusion which arose from these causes, 

 in a number of experiments made during the previous season, 

 which led me to think of the metallic labels. The whole manures 

 were then packed in casks, along with a quantity of Aberdeen 



