This collection conta ins the results of a number of investiga tions which have been carried out in the Hydrothermal Synthesis Laboratory of the Institute of Crystallography, Academy of Sciences of the USSR; it constitutes a continuation of an earlier collection which appeared in 1968: Hydrothermal Synthesis of Crystals. Problems associated with the synthesis of oxides, simple and complex sulfides, carbonates, silicates, and germanates are consid ered, and a great deal of factual material relating to the growth of single crystals of some of these compounds on a seed is presented. Some of the articles pay special attention to the kinetic asp ect of the growth of crystals; the conditions of growth are relat ed to the morphological characteristics of the growing faces, and the relationship between the habit of the crystals and the oomposi tion and constitution of the solutions is considered. A fair number of articles are concerned with the crystalliza tion of new compounds, most of which have now been synthesized under hydrothermal conditions for the very first time; these in clude ternary chalcohalides of composition AVBvIVVII. zirconates, lithium silicates, and germanates. The collection also contains a description of the apparatus used for precision measurements at high temperatures and pres sures. We hope that this publication will present a better idea of the special characteristics of the hydrothermal method of synthes izing and .growing crystals, and will prove useful to all those in terested in this field of knowledge.