Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Manures are substances which are incorporated with the soil for the purpose of supplying some deficiency in the latter. How ever numerous and different may be the materials which assist the growth of plants, judging them by their origin, external characters and names, chemistry has in late years demonstrated that they all consist of only about a dozen forms of matter, ~which will be specified below.