No. VIII.} EXPERIMENTS UPOV EEAt^S. 75 



did not increase the produce beyond that of an equal weight of sulphate alone. 

 This is different from the action of the latter salt in the case of the other grain 

 crops and of potatoes, • 



4° . That 1 c wt. of sulphate of soda produce as great an eifect as 1 6 cwt. of rape- 

 dust — the quantity of grain reaped from both applications being very nearly the 

 same. 



Siis'S;estio7i XL — These striking effects of the sulphate ultimately took place, 

 although when first applied to the young plants it burned and blackened theii 

 leaves. I trust that these results will also be tested by repetitions in other years 

 — less droughty, it is to be hoped — and in other parts of the country. For the 

 sulphate of soda, Mr. Alexander's experiment seems to say that gypsum, which 

 is still cheaper, may be economically substituted. 



5°. It will be seen that guano v;pon this crop, as upon the wheat already noticed 

 (p. 68), was less successful than some of the other substances employed. 



Conclusion. — Upon the observations of Mr. Gardiner in regard to the effect 

 of the dressings of 1841 upon the crop of 1842, I have nothing to add to the re- 

 marks I have already made (p. 57) upon their importance, and upon the good 

 that must follow from continuing them. But? in concluding these observations, 

 the reader will please to recollect that I have adverted to those points only, in the 

 above tables of results, which appeared to myself most important. There are 

 many other points to which by a careful study of the tables his attention will 

 naturally be drawn. He will consider the observations themselves also, as 

 only so many gropings after truth. The present state of our experimental inqui- 

 ries can scarcely be supposed as yet to give us more than a glimpse here and 

 there of the true light. Like a man who finds himself in a dark dungeon, we 

 are peeiing tlrrough the comparative gloom of our prison-house, in the hope of 

 finding some mode of escape into the upper day. Like him we may be long in 

 discovering the true outlet, and the passage upwards may be narrow and in- 

 tricate ; — but the same conviction which will give him safety, will ultimately 

 lead us also to the light — that he who, persists in trying — marking and recollect- 

 ing every turning he has explored — viay at length escape; but that he who sits 

 still, in indifference, or gives up his quest in despair, is sure to die in darkness. 



No. IX. 



ADDITIONAL EXPERIMENTS IN PRACTICAL AGRICULTURE, 

 MADE IN 1842. 



The following experiments were made at Erskine, in Renfrewshire, upon the 

 Home Farm of Lord Blantyre : — 



Experiment I. — Potato Oats, after old Grass. 



The soil was variable, chiefly good loam, resting on a subsoil partly gravel 

 and partly sand. The field, having been long in pasture, in many places very 

 wet, was drained in November and December, 1841 ; ploughed soon after, and 

 sown with oats on the 8th of April. The manures were applied on the 15th 

 of April, and harrowed in with a single stroke of the harrows. One-fourth of 

 an imperial acre being previously weasured off for each plot. 



According to notes taken of the appearance of the crop from time to time — 



May 23. — The nitrate of soda (No. 1) looking darker in colour than any of 

 the other plots; next to it, in point of colour, the foreign guano (No. 5) seems 

 best; then the soot (No. 9); then the sulphate of ammonia (No. 2); (?annot, 

 however, discern any very decided difference in the appearance of the othera 



