III. On a new series of organic compounds containing boron

The substitution of a compound organic radical for an elementary constituent in inorganic compounds has proved itself to be one of the most important and fertile fields of modern chemical investigation. The application of this species of substitution to the inorganic compounds of metals has called into existence an entirely new and extensive family of organic substances— the organo-metallic compounds, bodies never met with in nature, distinguished by their well-marked affinities, and capable in some instances of effecting, in their turn, numerous substitutions of a like character. The realization of a similar substitution in the case of certain inorganic compounds of nitrogen and phosphorus has, in the hands of Hofmann, not only enriched the science with a host of new and interesting compounds, but has also brought our knowledge of the organic bases to a degree of completeness, which cannot be rivalled in any other class of organic compounds. Lastly, attempts have not been wanting to extend these reactions to the oxygen com­pounds of the metalloids; and although this portion of the field presents difficulties of a somewhat more formidable character, yet these attempts have not unfrequently been attended with success. Thus nitric oxide has been transformed into dinitroethylic and dinitromethylic acids; sulphurous anhydride into ethylodithionic and methylotri-thionic acids; and carbonic anhydride into propionic and acetic acids. The last-named reaction, confirming, as it did, the view previously expressed by Kolbe and myself, that organic compounds in general are nothing more than substitutions of this nature effected in carbonic oxide, in carbonic acid, and possibly in other inorganic compounds of carbon, naturally awakened a desire to extend this inquiry to the oxygen compounds of boron and silicon, which are usually regarded as possessing certain im­portant analogies with carbonic anhydride. With this end in view, boracic ether was submitted to the action of zincethyl by Mr. Duppa and myself. W e found that the whole of the oxygen in boracic acid became replaced by ethyl, and in a short communi­cation to the Royal Society, we described some of the properties of the remarkable body, boric ethide, thus formed. In the further study of this substance, and the extenion of the research to the homologous methyl compound, I much regret having been deprived of the cooperation of my friend and fellow-labourer who had rendered me such valuable assistance at the commencement of the investigation, but who was reluctantly compelled to abandon its further prosecution.