With regard to phosphatic manures the same considerations hold good. Inasmuch as phosphoric acid, whether applied in the soluble condition, as in superphosphate, or the insoluble form, as in bones, basic slag, &c., is not liable to be washed out of the soil, the risk of loss is very slight, and need not be taken into account. As we have pointed out in considering the action of superphosphate, phosphoric acid in this latter form is more speedily available to the crop, and the necessity of applying it much before it is likely to be used does not exist. Hence superphosphate and manures which contain any appreciable amount of soluble phosphoric acid, such as guano, should only be applied shortly before seed-time. Bones, basic slag, or mineral phosphate ought to be applied, on the other hand, a long time before they are likely to be used. Hence an autumn application is to be recommended in the case of such manures. _Potash Manures._ Lastly, with regard to potash manures, as these are soluble, there is no necessity for applying them much before they are likely to be absorbed by the plant. Some are of the opinion that potash is, except in the case of sandy soils, best applied some little time before it is likely to be used, so as to permit of its being washed down into the soil--a process which takes place only comparatively slowly. As potash manures have often been found to give a better result on pastures during the second year than during the first, they are best applied in the autumn. The above statement as to the behaviour of the different fertilisers when applied to the soil, has a not unimportant bearing on the quantities in which they may safely be respectively applied. The rate at which manures may be applied depends, as we shall immediately see, on other conditions; but what it is here desirable to point out is, that it is not safe to apply such manures as nitrate of soda, or, for that matter, sulphate of ammonia, in large quantities at a time. In fact these manures, especially the former, will best be applied in very small quantities, and rather in several doses. With regard to other manures, more especially phosphatic manures, the same reasons for small application do not exist. The truth of the above statements is so obvious that it may be regarded as superfluous to make them. As, however, their clear apprehension is essential to understanding the conditions of successful manuring, no apology need be made for making them. _Nature of Soil._