Written for researchers in the chemical and pharmaceutical field, who deal with solubility, this book proposes a unique way of predicting aqueous solubility directly from the structure of a compound. The algorithm termed SCRATCH model utilizes predicted melting points and aqueous activity coefficients for the solubility estimation. Both the melting point and aqueous activity coefficient predictions are individually trained on over 1600 organic compounds, making the model very rigorous and robust. The model is cross- validated on about 900 organic compounds for the aqueous solubility prediction. In addition, the three appendices provide a lot of useful information for the reader.