94 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Among the different dyes derived from aldehydes, upon which 

 Bayer reported to the German Chemical Society in January 

 last, one excited a special interest, as its production appeared 

 to be one step further toward the synthesis of natural color- 

 ing matters. The first series of experiments led up to bodies 

 which, in their chemical relations, as apparently in their con- 

 stitution, stood very near to the dyes of logwood and Brazil- 

 wood. This time it is the pigment of green plants, or chloro- 

 phyl, which Bayer approaches in his synthetic experiments. 

 Furfurol, the aldehyde of mucic acid, and reforcine, or pyro- 

 gallic acid, furnish a substance having the reaction of chloro- 

 phyl. If, therefore, we can not actually speak of the syn- 

 thesis of the latter, because what has been hitherto termed 

 chlorophyl is scarcely a pure chemical body, but rather a 

 mixture of green pigment with protoplasm, we may still hope 

 to arrive at the green coloring matter of plants along the 

 path pointed out by Bayer, and consequently be able to clear 

 up its hitherto unknown chemical constitution. 1 9 C, March 

 9,1872,77. 



ARTIFICIAL MELLITIC ACID. 



Professor Schulze, of Rostock, has devised a method of 

 forming mellitic acid artificially by the direct oxidation of 

 carbon by permanganic acid in an alkaline solution. 13.4, 

 December 1, 1871,540. 



ON CHLOROPHYL AND ITS DERIVATIVES. 



Gerland and Rouwenhoff, in a paper upon chlorophyl and 

 some of its derivatives, sum up their inquiries in the follow- 

 ing propositions : 1. Not alone in chlorophyl, but also in such 

 derivatives as show, like it, the obscure, dark absorption band 

 I, this band is composed, for a certain degree of concentra- 

 tion, of two parts, separated by an interval which is but lit- 

 tle superior in brightness. 2. Once modified, chlorophyl ex- 

 periences no further changes. 3. Solid chlorophyl, whether 

 contained in the tissue of leaves or precipitated from a solu- 

 tion, shows the same absorption bands as chlorophyl in solu- 

 tion. 4. The phylloxanthine of Fremy seems to be simply 

 modified chlorophyl; his phyllocyanine is a derivative of 

 chlorophyl produced under the influence of an acid. 5. The 

 green and yellow matters of Filhol should be regarded as the 



