The dung of birds possesses the united virtues of both the liquid and solid excretions of other animals. It contains every part of the food of the bird, with the exception of what is absolutely necessary for the support and for the right discharge of the functions of its own body. It is thus fitted, therefore, to return to the plant a greater number of those substances on which plants live, than either the solid or the fluid excrements of other animals; in other words, to be more nourishing to vegetable growth. SECTION III.—OF THE RELATIVE GROWTH OF THE DIFFERENT ANIMAL MANURES. The fertilizing power of animal manures, in general, is dependent, like that of the soil itself, upon the happy admixture they contain of a great number, if not of all, those substances which are required by plants in the universal vegetation of the globe. Nothing they contain, therefore, is without its share of influence upon their general effects, yet the amount of nitrogen present in each affords the readiest and most simple criterion by which their agricultural value, compared with that of vegetable matters and with that of each other, can be pretty nearly estimated. In reference to their relative quantities of nitrogen, therefore, they have been arranged in the following order, the number opposite to each representing the weight in pounds which is equivalent to or would produce the same sensible effect upon the soil as 100 lbs. of farm-yard manure. Farm-yard manure, 100 Solid excrements of the cow, 125 ” ” ” horse, 73 Liquid ” ” cow, 91 ” ” ” horse, 16 Mixed ” ” cow, 98 ” ” ” horse, 54 ” ” ” sheep, 36 ” ” ” pig, 64 Dry flesh, 3 Pigeons’ dung, 5 Flemish liquid manure, 200 Liquid blood, 15 Dry blood, 4 Feathers, 3 Cow hair, 3 Horn shavings, 3 Dry woollen rags, 2½ It is probable that the numbers in this table do not err very widely from the true relative value of these different manures, in so far as the _organic_ matter they severally contain is concerned. The reader will bear in mind, however,