"Definition of Carbon and Hydrogen in Organic Compounds" by H. Gelman is a fascinating and in-depth study that immerses the reader in the world of organic chemistry, revealing the intricacies and nuances of carbon and hydrogen analysis in various organic compounds. This publication will be a real discovery for students, graduate students and specialists in chemistry, as well as for anyone interested in modern methods of analysis and research of chemicals. In his book, Gelman not only outlines the theoretical aspects, but also offers practical methods to accurately and effectively determine