284 



Dr. J. L. W. Thudichum. 



[Mar. 18, 



nitric acid, and the phosphorus estimated by precipitation with am- 

 nionic molybdate, and transformation of the precipitate into magnesio- 

 ammonic phosphate, &c. This gave 0*3266 grm. phosphorus, equal to 

 0*7480 grm. phosphoric anhydride. 



The filtrate was proved to be free from magnesium and calcium. 

 The potassium contained in it was extracted in the usual manner, by 

 means of platinic chloride, giving 11*2766 grms. of the double salt 

 (2KCl,PtCl 4 ) equal to 3*651 grms. potassic chloride, or 1*911 grm. of 

 potassium. The mother-liquor and washings were evaporated to dry- 

 ness, and the platinum was removed by extracting the ignited mass 

 with water acidified by hydrochloric acid. The extract so obtained 

 was evaporated to dryness and fused ; the residue weighed 3*45 grms., 

 being pure sodic chloride equal to 1*356 grm. sodium. The quantities 

 of sodium and potassium thus found were controlled by the analysis of 

 a separate part of the original solution containing their chlorides ; and 

 on calculating from the residue obtained on evaporation there should 

 have been found a total quantity of chlorides = 7*09 grms, There was 

 found potassic chloride = 3*651, and sodic chloride = 3*450 ; together, 

 7*101 grms. 



Assuming the above earthy bases to have originally existed in 

 myelin as tribasic phosphates, and any phosphoric acid remaining 

 over to have been in combination with potassium, then we have, 



Calcium . . = 0*1423 grm. existing as 3CaO,P 2 5 . 



Magnesium . . - 0*1212 „ „ 3MgO,P 2 B . 



Potassium . . = 0*5663 „ ,. 3K 2 0,P 2 5 . 



Potassium . . — 1*3447 ~l combined directly with 



Sodium .. = 1*3560 ,, J myelin. 



Phosphorus . . = 0*3266 ,, existing as P 2 5 (0*748 grm.) 



and distributed between the calcium, magnesium, and potassium. 



In the kephalin research, related above, it was proved that kephalin 

 was partly in combination with calcic oxide or lime, without any other 

 acid being united with that base. In the myelin research it was found 

 that, in myelin, there may be in combination even a much greater 

 quantity of potash and soda than of lime. 



A third research was now made on the mixture of phosphorised and 

 nitrogenised substances, which Premy termed " cbrebric acid," and 

 which later writers have termed "protagon." This, after exhaustion 

 with ether, was redissolved eight times in hot spirit, and after filtra- 

 tion reprecipitated on cooling. It was pressed to remove all mother- 

 liquor, was then suspended in water and heated until it became 

 thoroughly emulged with it ; acid, either sulphuric or hydrochloric, 

 was now added, whereupon the organic matter curdled and con- 

 tracted ; it was separated, and the acid solution was treated like the 

 above described similar solution' from kephalin and myelin. Con- 



