The Substance of Homoeopathy starts systematizing the wealth of ideas first discussed in the Spirit of Homoeopathy. New thoughts on the periodic table of elements and an expanded theory of the miasms are now used to order the material presented. This book is valuable for the differentiation of various salts, which partially anticipates Scholten's method of mineral analysis. The most interesting part is the new theory of miasms, which comes to fruition in An Insight into Plants