p &EQIQQY Art. XV . — Analyses of the Waters of some American Alkali Lakes ; by Thomas M. Chatard. In the course of the geological examination, by the II. S. Geological Survey, of the Great Basin or country lying be- tween the Rocky Mountains and the Sierra Nevada, samples of the waters of most of the lakes of that section were collected and sent for analysis to the laboratory of the Survey. Many of these analyses were published in Bulk No. 9, U. S. Geol. Survey, but when I began a special study of the more import- ant sources of natural alkalies, for the purpose of preparing the way for their practical utilization, a re-examination was, in some cases, deemed advisable and samples were also obtained from Owen’s Lake, California, a locality not visited by the Great Basin party. The four analyses here given represent the most important alkali lakes so far known and as the waters of two of them are now being utilized, it is believed that the information will prove of interest. The analytical methods used are, in general, well known. The carbonic anhydride was, in jail ases, determined by dis- / v