WITH THE SALTS OF AMMONIA. 211 



quantity applied ? Is it influenced by the time of applying it, 

 by the weather, by the soil, &c. ? 



3. Is the sulphate most favourable to leguminous crops, as 

 other sulphates are supposed to be ? Are the onion and the 

 cabbage especially influenced by it ? 



4. To the scientific agriculturist, the nitrate and the muriate 

 may be especially commended. Do they equally favour any 

 given crop ? Are their actions equally affected by dark and by 

 bright or sunny weather ? Does the nitrate or the sulphate 

 more especially demand the presence of the sun ? 



5. Are their effects always more favourable on light and 

 open than upon stiff clay soils ? May they not be profitably 

 used on all young crops on any soil, when the crops are yellow, 

 sickly, and stunted in their growth ? 



6. Are they especially indicated for use on deaf soils, or 

 such as contain much inert vegetable matter on such as are 

 poor in organic matter on soils newly trenched or turned up 

 from a depth, and so on ? 



7. Can they be used with safety for any and for what crops, 

 on soils which have already a tendency to produce a large 

 growth of straw or of tops ? 



8. Is a crop of any kind increased by different doses of the 

 same salt, in proportion to the quantity of nitrogen applied ? 

 Are the comparative effects of two different salts directly or 

 otherwise proportional to the quantity of nitrogen they sever- 

 ally contain ? If not generally, is this the case in regard to 

 any one crop in any given circumstances ? These questions 

 have been discussed in the preceding sections, and all the field 

 results we at present possess seem to answer both questions in 

 the negative. 



9. The nitrogen in the nitrate of ammonia is in two states 

 partly in that of nitric acid, partly in that of ammonia. Are 

 both these forms of nitrogen equally efficacious in this or that 

 circumstance of soil, weather, plant, or period of growth? 

 Will a nitrate of potash, soda, or lime, which contains as much 

 nitric acid as the nitrate of ammonia, produce an equal effect 

 with this salt of ammonia upon any plant in any circumstances? 

 Will a sulphate or muriate of ammonia, containing as much 



