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ON PROTAGON: ITS CHEMICAL COMPOSITION AND PHYSICAL CONSTANTS, ITS BEHAVIOUR TOWARDS ALCOHOL, AND ITS INDIVIDUALITY
Author(s) -
Wilson R. A.,
Cramer W.
Publication year - 1908
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0370-2901
DOI - 10.1113/expphysiol.1908.sp000004
Subject(s) - alcohol , chemical composition , crystallization , chemistry , composition (language) , decomposition , molecule , organic chemistry , thermodynamics , physics , philosophy , linguistics
1. Protagon is a substance of a definite chemical composition, retaining this composition after repeated recrystallisation. 2. Protagon is a substance with definite and constant physical properties. The specific rotatory power and the refractive index of several samples of protagon have been determined. 3. Protagon is identified by its chemical composition and by its physical constants. Many substances to which the name protagon has been given on account of their method of preparation, do not conform to these conditions, and therefore have no claim to the name protagon. Couerbe's cerebrote is not identical with protagon, but probably a mixture of substances of which protagon is one. 4. Protagon is decomposed by a prolonged treatment with warm alcohol. The so‐called process of fractional crystallisation is therefore in reality a process of partial decomposition. The conclusions which have been drawn on the assumption that it is a process of recrystallisation are not valid. There is, consequently, no evidence for the view that protagon is a mixture f cerebrosides and phosphatids. 5. The constancy of the physical and chemical properties of protagon support the view that protagon is a definite compound. The substances isolated from protagon after prolonged treatment with warm alcohol, and formerly held to exist as such in the mixture protagon, must now be considered to be the constituents of the protagon molecule. They are the intermediate decomposition products of protagon. 6. Details of a method for the preparation of protagon are given, by means of which a prolonged contact with warm or boiling alcohol can be avoided as much as possible.