1880.] Modifications of the Spectrum of Potassium, Sfc. 283 



evaporated to dryness, ignited, and the residue tested for alkalies. 

 This residue exceeded in bulk the bases previously removed. It was 

 fusible with ease, and on solidification became white and crystalline, 

 but interspersed with many red particles of ferric oxide. It was a 

 mixture of potassic and sodic chlorides, and of some ferric oxide, which, 

 owing to the presence of the chlorides, had escaped precipitation by 

 excess of ammonia. 



It was, therefore, proved that the kephalin, obtained by the alcohol 

 and ether process, and purified by solution in water and filtration, as 

 described at length in my researches above quoted, is, at least in part, 

 combined with ammonium, sodium., potassium, calcium, iron, copper, and 

 calcic and magnesic phosphates. This experience was repeated a great 

 number of times, and, in the aggregate, on several hundred grams of 

 dry kephalin. 



In the following experiments myelin (the phosphorised ingredient 

 which stands next in importance to kephalin in the chemistry of 

 the brain)* was examined for inorganic bases, in order to obtain 

 some knowledge regarding their relative amounts and nature. The 

 myelin was dissolved in water, precipitated by hydrochloric acid, and 

 the acid solution separated by filtration. The copper was removed by 

 hydrothion, the filtrate evaporated to dryness, and the residue ignited 

 in a platinum dish. During this ignition much amnionic chloride was 

 given out, and its nature distinctly proved by condensing and analys- 

 ing it. * 



The fused mass was dissolved in dilute hydrochloric acid, and the 

 solution so obtained treated with excess of ammonia. The white 

 gelatinous precipitate which was thrown down was scarcely coloured 

 black by ammonic sulphide, indicating the presence of only a trace of 

 iron. The precipitate and filtrate were submitted to analysis, qualita- 

 tive and quantitative, as follows : — 



The precipitate was dissolved in dilute hydrochloric acid, the solution 

 was nearly neutralised by sodic carbonate, after addition of some ferric 

 chloride ; an excess or barytic carbonate was now added ; the mixture 

 was shaken, allowed to stand, and then filtered. Erom the con- 

 centrated filtrate the barium was then removed by sulphuric acid, 

 and the filtrate was precipitated in the presence of excess of ammonia 

 by ammonic oxalate. The oxalate so obtained was converted by 

 intense ignition into oxide, which weighed 0*1994 grm., equal to 

 G'1423 grm. calcium. The filtrate and washings from the calcic 

 oxalate were treated as usual for the quantation of magnesium, and 

 there was obtained 0'5556 grm. magnesic pyrophosphate, equal to 

 01212 grm, magnesium. The precipitate which had been produced 

 by ferric chloride, and sodic and barytic carbonates, was dissolved in 



Eeports, as above, No. Ill, p. 156. 



