Manurial Properties of Clay from Gas- Works. 309 



it laid exposed to snow, rain, wind, sunshine, and all the count- 

 less changes of our most changeful climate. About thirty tons 

 were fetched away by a farmer on the 30th April, 1856, and shut 

 up in an open yard as freely exposed as before. Much ammoni- 

 acal and other gas was given off, as a plot of potatoes proved 

 which was about forty yards distant, for all the foliage was 

 destroyed when a north-east wind brought the gases across the 

 plot. Part of the heap was removed to a pasture, where the 

 course of drainage could be traced for more than a hundred yards 

 by the destruction of the grass. In January, 1857, the heap had 

 been subjected to the full influence of weather for upwards of 

 twelve months, when part of it was used to manure the ten-acre 

 meadow before mentioned. Opinions were freely expressed on 

 the impossibility of an artificial manure retaining any virtue after 

 such treatment, and the use of a substance thus dealt with was 

 certainly an experiment of the highest agricultural interest and 

 importance. The result is, that the grass of that field dressed 

 with this alone grew luxuriantly and too early, for it was nipped 

 by the biting east winds and sharp night-frosts which prevailed 

 so long in the spring, and that now (May 30th) on the dry parts 

 of the field is growing the most abundant crop of grass which I 

 have seen this year. If not mown early, it will be laid as the 

 grass of the same field was last year, and, in the case of wet, will 

 rot in the bottom. 



The " potato-disease " has an interest for every one, whether 

 he be a producer or consumer ; and as an experiment of last year 

 bears upon the subject it should be known. I planted 3 acres 

 of Prince Regent potatoes, to 2^ acres of which a quantity of tliis 

 new manure was applied, mixed with the heap which would 

 otherwise have been used alone. Half an acre had none. The 

 heap was badly mixed, so that in parts there was a large excess, 

 and in parts hardly any. Time prevented a second turning, and 

 it was used with all its defects. The whole crop grew well, and 

 no great difference was apparent for a time. At length the disease 

 appeared badly in all the district, and after a time the tops be- 

 came diseased and died av,ay. I sold the crop on the ground to a 

 dealer, who, as well as his men, assured me that where the " blue 

 stuff" was there was no disease, or, if any, very little ; while, where 

 none of this could be found, the principal portion of the crop was 

 affected. To test their assertions, I requested them several times 

 to dig up portions of the crop in various parts of the field, and found 

 that the statements they made were entirely corroborated. I Avas 

 prepared for the better crop which accompanied the special ma- 

 nure, but its influence over disease was entirely unexpected. I 

 think also it is unexplained. If^^^ disease be owing to the attacks 



VOL. XVIII. Y 



