PROTAGON, A DEFINITE PROXIMATE PRINCIPLE IN THE BRAIN.

Globe, Volume XXII, Issue 1839, 14 January 1880, Page 3

PROTAGON, A DEFINITE PROXIMATE PRINCIPLE IN THE BRAIN.

In the year 1865 Dr. Oscar Liebreich published a memoir in which he announced the discovery in the brain of a definite proximate principle containing phosphorus. Unlike the numerous bodies possessed of ill-defined properties, which had by different writers received tho names of cerebrin, cerebric acid, lecithin, or phosporized fats, this new body could be extracted by an easy process in a ■tate of purity, and it is, probably to indicate it as the first definitely specific constituent of brain matter, Dr. Liebreich gave the name of "protagon." The brain was subjected to a special process by which the protagon was separated in the form of microscopical needlelike crystals, differing a little in arrangement and form according to the concentration of the solution. As the result of several anaylses Liebreich ascribed to protagon the formula 0116, H 241, N 4, 022, P. It was difficult of solution in cold alcohol, more easily so in warm alcohol and ether. In water it swelled and presented the appearance of an opaque jelly, ultimately dissolving so bb to form an opaque solution. For a time observers admitted it to be a definite phosphorized constituent of the brain, and they began to seek for it in various liquids and solids of the body. Hermann announced its discovery in the blood corpuscules, and connected many of the physical properties of these bodies with its presence. Parke found it in the yolk of egg, but Hoppe-Seyler thought that the yolk of egg contained not protagon but lecithin, and though this very distinguished investigator did not commit himself to a denial of the existence of protagon in the brain, still he seemed to have commenced to entertain some doubts about it. In 1868, however, Dr. Diaconow, a pupil of Professor HoppeSeyler's, published a paper on the subject, which seemed to have an immense influence over the physiological chemists, causing them all to come to the conclusion that Liebreich's protagon did not exist as a definite proximate principle, but that it consisted of a mixture of lecithin with a body free from phosphorus, cerebrin, and causing the master himself to write, "as to protagon, I believe that I must decide for its being a mixture of some glucosid free from phosphorus, as cerebrin, with leoithin," and so the matter rested until recently, when the whole subject was once more most carefully re-investigated in the physiological laboratory of O wenß College, Manchester, by Professor Gamgee, F.K.S., and Mr E. Blankenhorn. The process employed in the preparation of protagon and the results of the ultimate analyses [thereof, with a very intercsting account of all its] previous history, will be found in the current number of Professor Foster's]" Journal of Physiology." .As to the result, the fact of Liebreich's discovery is now left beyond a doubt, but the empirical formula for thi» important principle would appear to be 0168, H 306, N 5, Po3s— alteration from Liebreich's, in all probability owing to the extreme care and the improved methods employed in these late investigations.