The Indian Academy of Sciences This book was scanned by the Servants of Knowledge, a collection of volunteers dedicated to promoting the increase and diffusion of knowledge. The Servants of Knowledge gratefully acknowledges the contribution of the Indian Academy of Sciences to our efforts by providing space and logistical support in Bangalore. Jai Gyan! This specific book was generously donated for digitization work by Dr. Y. C. Kamala with permissions to make them available under Creative Commons.