65 TALKS ON MANURES. 



Dr. Voelcker draws the following conclusions from his experi- 

 ments : 



" Having described at length my experiments with farm -yard 

 manure," he says, " it may not be amiss to state briefly the more 

 prominent and practically interesting points which have been 

 developed in the course of this investigation. I would, therefore, 

 observe : 



" 1. Perfectly fresh farm-yard manure contains but a small pro- 

 portion of free ammonia. 



" 2. The nitrogen in fresh dung exists principally in the state of 

 insoluble nitrogenizecl matters. 



" 3. The soluble organic and mineral constituents of dung are 

 much more valuable fertilizers than the insoluble. Particular 

 care, therefore, should be bestowed upon the preservation of the 

 liquid excrements of animals, and for the same reason the manure 

 should be kept in perfectly water- proof pits of sufficient capacity 

 to render the setting up of dung-heaps in the corner of fields, as 

 much as it is possible, unnecessary. 



"4 Farm-yard manure, even in quite a fresh state, contains 

 phosphate of lime, which is much more soluble than has hitherto 

 been suspected. 



" 5. The urine of the horse, cow, and pig, does not contain any 

 appreciable quantity of phosphate of lime, whilst the drainings of 

 dung-heaps contain considerable quantities of this valuable fer- 

 tilizer. The drainings of dung-heaps, partly for this reason, are 

 more valuable than the urine of our domestic animals, and, there- 

 fore, ought to be prevented by all available means from running 

 to waste. 



" 6. The most effectual moans of preventing loss in fertilizing 

 matters is to cart the manure directly on the field whenever cir- 

 cumstances allow this to be done. 



u 7. On all soils with a moderate proportion of clay, no fear 

 ncvd to be entertained of valuable fertilizing substances becoming 

 wasted if the manure cannot be plowed in at once. Fresh, and 

 even well-rotten, dung contains very little free ammonia ; and 

 since active fermentation, and with ifc the further evolution of 

 free ammonia, is stopped by spreading out the manure on the 

 field, valuable volatile manuring matters can not escape into the 

 air by adopting this plan. 



" As all soils with a moderate proportion of clay possess in a 

 remarkable degree the power of absorbing and retaining manuring 

 matters, none of the saline and soluble organic constituents aro 

 wasted even by a heavy fall of rain. It may, indeed, be questioned 



