The most advanced portions of physics have already reached this point. Take, for instance, the study of gravitation. There was not perhaps a single scientific man of any importance in the XVII. century, even long after Galileo, who did not construct or adopt a system concerning the fall of bodies. At that time any science on this subject seemed impossible without a hypothesis of this kind. Who troubles himself with it to-day? We may be allowed to think that the other parts of physics will follow the same line, and that in turn they will conform to this rule of the positive method: “Every hypothesis must bear exclusively upon the laws of phenomena, and never upon their modes of production.” III. In the series of the fundamental sciences Chemistry appears to fill a somewhat secondary and subordinate place. In it the positive method is not enriched by any process of capital importance, but it confines itself to developing the processes already made use of in physics. In spite of appearances, even experimenting is less easy and less fertile in chemistry than in physics. The only new process which we see appearing is the art of nomenclature. Whenever we wish to study this art “at its source” we shall have to refer to chemistry.[140] The phenomena which it studies are the most complicated of the inorganic world. If then physics is extremely imperfect, it is not surprising that chemistry should be much more so. In the greater number of its researches “the chemistry of the present day hardly deserves the name of science.”[141] But this inferiority of chemistry is not only due to the nature of its object. There are other causes which it would be easier to remedy. The progress of chemistry is retarded: 1, by the wrong direction given to much of its work up to the present time; 2, by the defective education of the majority of the scientific men who give themselves to its study.