supplement. SCIENCE AND ART OF AGRICULTURE. 



1309 



sump nous nor over sanguine in expressing my hope that the Society will give the subject their best 

 consideration, and afford such aid as may seem to them best calculated to lecure the co-opera ion of 

 pracical agriculturists, in instituting and reporting the results of experiments, ca eful y made on a 

 regular and systematic plan We may not succeed to the full extent ; but I cannot help hmking that a 

 wide, fertile and unexplored field .n agricultural improvement lies before us : and alth h gh it would be 

 rash to venture an opinion as to the results which the combined effect of science and [ enlleht ened 

 •1™'"™)' »™ e at. it would be equally rash and less politic, I apprehend, to rest sat sfiedwltl our 

 present knowledge. Let practical men, therefore, establish facts by experiments caref 1 v made 

 whether from the suggestions of their own mind or those of others ; and let the duty of trac na TthesT to 

 the prmciples of nature on which they depend, be zealously discharged by men of sdence -and perh ,ns 

 the progress may be more rapid, and the success greater, than it would be either wise or prudent to an- 

 ticipate at present." (Tra7is. H. S., vol.xiv. p. 526.) F ' 



8145. Exper- 

 may be depe 

 18-12, presen 

 the crop mowed on the 10th Vf August. "^The'soTl'was'raTher poor, cooristing'of a heavVday 



corn ifiio uZ T WiVi YmR ""HT ! COr " P 7 aCre ' M13 loS - 2 ' With 28 lbs - of sulphate of ammonia ; 

 com' on? m ?■ SfS ?2 u*' ° th f same salt ; com ' 1999 lbs - 4 - With 112 lus - of nitrate of soda 

 mSOm . ' !.!'£• ° f 'V, tre ; l ' 0r "' 1890 lDS - The increase in thp str aw was also consider^ 



able in all cases, except with the small proportion of sulphate of ammonia. The total increase in the 

 lour manured crops was, per cent, in the order in which they were enumerated, 14-1, 415 34 and 335 •' 

 the cost of the manure for the three last did not greatly differ, being 21s. ilrf., 24s. 6rf 27? 6rf The profit 

 on the outlay was, with the small dose of sulphate of ammonia, 294 per cent : with the large dose 21 2 per 

 cent ; with the nitrate ol soda, 138 per cent ; and with the nitrate of potash, 92 percent. The principal 

 conclusions drawn by the author are, that the increase of the nitrogen in the crop is greater than is ac- 

 counted for by the nitrogen of the manures, showing that these manures have a stimulating effect or 

 enable the plants to draw additional nitrogenised food from the soil and atmosphere ; the considerable 

 superiority of sulphate of ammonia over the other salts, and the greater proportional efficiency of a small 

 than o a large dose ol that salt. The sulphate of ammonia costs 17s. per cwt. It appears best to aonlv 



about twice the quantity of common salt or of soot may be mixed with the ammoniacal salt. These and 

 most saline manures, when used as top-dressing, should be supplied to the plant, when dry, some 'time 

 alter a shower of rain, or during hazy weather." (G. C. 1842, p. 839.) 



8146. Ammoniacal salts as manures. In Switzerland, water is poured over the fresh stable-dung so as 

 to wash it . ; the fluid thus obtained is saturated with sulphate of iron, or sulphuric acid and a liquid 

 manure of great power is the result. It has for many years been the custom in Switzerland to preserve 

 stable urine, to wash the fresh manure, and to collect the fluid in reservoirs, where, after fermenta ion 

 has taken place, the ammonia is saturated and converted into sulphate of ammonia by sulphate of iron 

 (green vitriol) sulphate of lime (gypsum), or sulphuric acid (common vitriol). The fluid thus obtained 

 wnen employed for watering land, produces a strong vegetation, an effect that is ascribed to the sulphate 

 ot ammonia, which is not volatile, like the carbonate, if acted upon by the sun. Fresh manure like urine 

 contains ammonia, which it is important to preserve, but which is generally wasted by the common modes 

 of managing manure. (G. C. 1842, p. 191.) 



"Dr. Sprengel, after describing the various methods of employing liquid manure, uses these strong 

 words : — V\ hoever is obliged for want of straw to collect the urine separately whoever, if he be com- 

 pelled to do this, mixes no water with it, or who fails also to emplov some neutralising substance to com- 

 bine with the ammonia, which is produced in so great a degree during the summer, — suffers a loss of 

 manure which exceeds all belief. It is, indeed, only a gaseous substance, and not a solid material 

 visible to the eye which thus escapes and is lost ; but for all that, it is of greater importance to the 

 plants than any other portion of the droppings.' " (Jouin. A. S. E., vol. iii. p. 208 ) The quantity of 

 sulphuric acid required to fix the ammonia of urine in a state f putrefaction is 12 per cent. ■ of muriatic 

 acid, 34 per cent ; or by weight, 12 lbs. of sulphuric acid, 34 of muriatic acid, or 154 of sulphate of lime to 

 nx the same quantity of ammonia. (G. C. 1842, p. 51.) 



8147. To ascertain whether or not a liquid contains free ammonia. Take a tea-spoonful of common 

 turmeric powder, and mix it into a thin paste, with a little water ; keep aside one-half of the greenish 

 yellow paste thus formed, and mix the remainder with three or four times its bulk of the liquid to be ex- 

 amined If it contain any free ammonia, the liquid becomes immediately of a reddish brown colour • 

 tlie depth of the colour depending on the quantity of free ammonia it contains ; upon the addition of a 

 lew drops of any acid the ammonia will be neutralised, and the turmeric will return to its original yellow 

 colour. J he value of any acid or other substance as a fixer of ammonia may be well tested in this 

 manner ; the liquid must be mixed with a little of the powdered root, which it will immediately redden, 

 the value of the fixer, or the quantity of it required for any quantity of the manure, is known by ob- 

 serving how much ol it must be added to bring back the original yellow colour of the turmeric. Turmeric 

 root may be procured at almost any chemist's ; if only the whole roots can be obtained, they are readily 

 rubbed to powder on a common grater, like ginger. ( E. Solly in G. C.1842. p. 868. 



8148. Test for the presence of Ammonia. A strip of paper previously rubbed over with petals of the 

 common mallow will be turned green, if the ammonia predominate in the liquor. The absence of the 

 ammoniacal smell is a very uncertain proof of the saturation of the ammonia by the sulphuric acid and 

 the use of the test will save the waste of acid. (G. C. 1842, p. 742.) 



I 1 . 4 . 9 - , Nitrate of Soda. The effect of this manure in increasing the value of the hav crop has been 

 strikingly exemplified in numerous instances. Mr. Grey, of Dilston, dressed one portion of a field with 

 nitrate of soda, another portion with manganese and nitrate of soda in equal quantities, and a third portion 

 was left without any dressing. This was done in May, at the expense of 26s. per acre for the nitrate ot 

 soda, and 21s. for the nitrate and manganese, and when the hay was made the produce was found to be 3 

 tons 88 stone in the former case, 3 tons and 21 stone in the latter, and only 2 tons and 37 stone on the 

 space which received no dressing. (Trans. H. S., vol. xiv. p. 330.) 



8150. Natural silicate of potash for manure. Potash being drawn from the soil by every crop requires 

 constant renewal. The ordinary resources are, vegetable ashes of different kinds, such as wood some 

 kinds of peat turf, weeds, leaves, and even straw. The potash in the food both of man and beast is 

 restored chiefly in the form of liquid excrement, which runs to waste in our town sewers, or in our farm- 

 yard drainings. Liebig proposes to procure the silicate of potash from the ashes of burnt wood but 

 Mr. Prideaux, an eminent Plymouth chemist, suggests the idea of obtaining it from Dartmoor or other 

 granite, by burning and mixing with lime. The details of the process will be found in the Brit. F M 

 N. S., vol. vii. p. 102. 



8151. Effect of mixed manures. " It is probable that one of the reasons why natural manures are so 

 much more valuable than any of the simple manures, is their consisting of many different ingredients, 

 so that if one does not take effect upon a crop, another may. Thus we see that farm-yard dung guano' 

 cloacine, and compost-heaps, produce invariably a good effect ; while nitrate of soda, sulphate of soda, and 

 the other saline ingredients now so extensively employed, sometimes succeed, sometimes fail, and always 

 succeed best when used in addition to the ordinary manures. Experiments show that plants are but little 



