390 PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 



Yellow Turnip Seed, supplied by Messrs. Drummond and Sons, 

 of Stirling, so that each experimenter was placed in precisely 

 the same condition, both as regards manures and seed. 



With each lot of manures, a letter of advice was dispatched, 

 and a set of instructions, of which the following is a copy : — 



Instructions for laying out the Plots and sowing the Manures far 

 the Field Experiments of Season 1866. 



1. Select a portion of the field in which the soil is as uniform 

 as possible, avoiding headlands. 



2. At 5 or 6 different places dig a small trench 10 inches 



deep, and from the side of it take a 



slice with the spade about 3 or 4 



inches thick, as represented here. 



Mix the whole in a barrow, and 



take from this 5 or 6 lbs. as a sample of the soil. Go down 



other 10 inches and take a similar sample of the subsoil. Small 



bags and labels for these are sent along with the manures. 



3. Let the drills in all cases be 27 inches wide. 



4. Fix a stake in the corner of the space selected for the ex- 

 perments, and having counted the number of drills required for 

 the plots, fix at the opposite end another stake, so that the line 

 between the two may be at right angles to the drills. It will be 

 found convenient to stretch a string between the stakes and to 

 let a man walk along treacling on the top of the drills, so as to 

 make this line distinctly visible. 



5. It will be most convenient to take 4 drills as the width of 

 each plot, but should circumstances render it necessary, they 

 may be made 6 drills wide. 



6. If 4 drills be selected as the width, measure off along the 

 drills from each stake a length of 43 feet 2 inches, and fixing 

 stakes at these points, stretch the string between them and mark 

 the line as before. Measure off another equal space along the 

 drills, fix stakes and mark as before. There are thus obtained 

 two parallel spaces, between which any 4 drills will be yL of 

 an acre. Should it be resolved to make the plots 6 drills wide, 

 the distance between the stakes must be 28 feet 9 inches. 



7. The Experiments are in two different series, marked 1st 

 Series and 2nd Series. 



1st Series. — Experiments with Soluble Phosphates, from 

 types of the great sources, Minerals, Bone-ash, and 

 Guano, with comparison between Gelatine and Sulphate 

 of Ammonia. 



These Experiments are founded on the principle of applying 

 the manures in such quantity as to supply 112 lbs. of Soluble 



