112 



Prof. Gamgee. A Note on Protagon, [Jan. 29, 



searches, "were already several years ago extended to the product 

 termed ' protagon ' ; and this, too, was found to contain inorganic 

 constituents irremovable by recrystallization from alcohol, however 

 frequently repeated. It was found more particularly that ' protagon ' 

 and the bodies into which it can be separated, according to my re- 

 searches, always retain considerable quantities of potassium in com- 

 bination. As the quantity of inorganic ingredients in ' protagon ' 

 had never been estimated, I prepared a specimen of this matter, and 

 on analysis found it to contain the better part of 1 per cent, of in- 

 organic incombustible matter, phosphoric acid not included, and in this 

 no less than - 76 per cent, of the 'protagon' of potassium." * 



Having described various experiments in which the above impure 

 body is supposed to have been resolved into bodies which Dr. 

 Thudichum has elsewhere described as proximate principles of the 

 brain, he proceeds : " The foregoing data enable us to attribute their 

 proper value to the series of operations by which the advocates of 

 ' protagon ' have brought about the concordance of their analyses. 

 The potassium, which, though present in such quantity that if ' pro- 

 tagon ' were a unitary body its atomic weight would thereby be fixed, 

 they have not found, is calculated as oxygen ; the phosphate of lime 

 which they have not extracted, is made to increase the protagonal 

 phosphorus ; the mixture of the myelins, which they have not extracted, 

 and which they are unable to diagnose, is adjusted by solvents to a 

 convenient quantity, and made to represent the constituent phosphorus 



of protagon The uniform chemical composition 



of the brain greatly favours the obtaining from it, by the aid of 

 processes nearly akin to trimming, of extracts of uniform composi- 

 tion ; this uniformity can be greatly aided by limitations of the 

 quantities of materials operated upon, and of the quantities and 

 strengths of the solvents ; and by careful observance of these limita- 

 tions, preparations are obtained which present a delusive appearance 

 of definiteness. But this delusion could only be persevered in by 

 persons who are not in the habit of subjecting their products to 

 tests of purity, and who are not acquainted with the necessity, which 

 is imposed upon every conscientious inquirer, of questioning his pro- 

 ducts and conclusions in a sense adverse to his hypotheses." 



After reading the above remarks, I determined upon placing in the 

 * The words printed in italics leave some doubt as to the author's meaning. It 

 might be supposed that by " 0'76 per cent, of the ' protagon' of potassium" he did 

 not mean 0'76 per cent, of potassium, but much smaller quantities. Lest there 

 should be any doubt on this point it is necessary to quote the following passage, in 

 which the statement is repeated in plainer terms : — " The remaining 30 grms. of 

 protagon once recrystallised (product IN" 1*2) contained l - 057 per cent, of phosphorus 

 and 0'76 per cent, of potassium." It therefore appears that in the sentence quoted 

 in the text the author means that the potassium amounted to 0*76 per cent, of the 

 protagon. 



