— 198 — 



Before the Societe chimique de France, G. Blanc 1 ), the French 

 chemist who has made himself well-known as a successful investigator 

 in the domain of camphor and allied compounds, read a paper on the 

 History of the Research into the Constitution of Camphor, 

 which, in its essence, runs on parallel lines with the history of the 

 synthesis of camphoric acid, the principal derivative of camphor. The 

 very detailed paper of course deals only with known facts in historical 

 order, and it is therefore unnecessary for us to enter into particulars 

 of it, but we desire to correct some of the author's statements. Blanc 

 does not do justice to the sequence of events when he traces the 

 establishment of Bredt's camphor-formula, (which apparently he ac- 

 knowledges with some reluctance) to the formation of dimethyl mal- 

 onic acid from camphoric acid observed by Koenigs. Apart from 

 the circumstance that Bredt had already published the facts from 

 which he deduced his formula before Koenigs' paper appeared 2 ), that 

 formula was based upon Bredt's own observation, (subsequently elab- 

 orated by A. Helle in the form of a dissertation,) that the first 

 decomposition -product of camphoric acid, viz., camphoronic acid, is 

 split up by dry distillation into trimethyl succinic acid, /^butyric acid, 

 carbon dioxide, water, and carbon 3 ). Nor is the assertion well-founded 

 that Bredt did not adduce a shadow of proof in support of his theory. 

 That scientist, on the contrary, most clearly stated and proved by 

 experiment that certain properties of camphoric acid and of homo- 

 camphoric acid, such as the formation of anhydride, the caloric value, 

 etc, must needs lead to the conclusion that the former acid was a 

 substituted glutaric acid, and the latter an adipic acid. These views, 

 it is true, could not be brought into harmony with Bouveault's for- 

 mula so warmly championed by Blanc at the time. On the occasion 

 of the well-known debate at the Naturforscherversammlung at Brunswick, 

 Bredt finally disproved the correctness of Tiemann's camphor formula. 

 Bredt at first then pointed to the parallellism of the conversion of 

 a-campholenic acid and of a-campholytic acid into the corresponding 

 /?-isomerides, and thereby cleared up a contradiction which had been 

 observed, but not explained, by Blanc himself. It will be sufficient 

 merely to quote these achievements of Bredt. It would be difficult 

 to understand how Blanc could maintain that it was partly the op- 

 ponents of Bredt's formula who afforded the proofs of its correctness, 

 if to this assertion he had not added the sentence : "ceci dit uniquement 

 pour montrer que la manifestation de la ve'rite' prime toute consideration 3 '. 

 This shows how hard Blanc finds it to acknowledge Bredt's formula. 



*) Bull. Soc. chim. IV. 5 (1909), Supplement to No. 9 of May 5th. 



2 ) Berl. Berichte 26 (1893), 2337. 



3 ) Berl. Berichte 26 (1893), 3047. 



