152 CHEMICAL COMPOSITION OF NUCLEI OF LLOOD COKLUSCLES. 



of hydrogen ; the nuclei, after treatment by ether and water, do 

 so also but less vigorously. 



When boiled with dilute sulphuric acid they gave no trace of 

 sugar. 



I have never succeeded in obtaining them free from sulphur 

 even after repeatedly dissolving in potash, and precipitating and 

 washing by acetic acid ; but the more carefully they were 

 cleaned the less sulphur was found ; and Professor Kiihne on 

 one occasion obtained no trace of sulphur after burning with 

 nitrate of potash and adding chloride of barium. This trace of 

 sulphur may possibly depend on a little albumen carried down 

 with the mucin ; more especially as one sees that if the haamo- 

 globin be not entirely removed by washing before dissolving in 

 potash and precipitating by acetic acid, htematin is constantly- 

 carried down with the precipitate, and cannot again be sepa- 

 rated. 



When chicken blood is treated by NaCl solution of 10 per 

 cent., as in Professor Heynsius' experiments lately published, 

 the nuclei are dissolved and form a lai'ge portion of the 

 fibrincus-iooking substance he describes. 



Whether mucin exists in mammalian blood or not I cannot 

 certainly cay, though the substance got by treating dogs' blood 

 with salt solution of 10 per cent., and then washing the slimy 

 mass, seemed, after solution in potash, to give a precipitate with 

 acetic acid insoluble in excess. The quantity obtained pure was, 

 how^ever, so small that I was unable to try any other reaction. 



Shortly, then, the substance of the nuclei, both with and 

 without the stroma, agrees with mucin, and differs from 

 albumin in its insolubility in HCl of 01 to 1 per cent., in its 

 alkaline solutions being precipitated by nitric, hydrochloric 

 or sulphuric acid, and the precipitate dissolved without diffi- 

 culty by excess ; in being precipitated by acetic acid, and the 

 precipitate insoluble in excess, ferrocyanide of potassium 

 causing no further turbidity, but clearing up any formed by the 

 acetic acid ; in neutral solutions being unchanged by boiling, 

 and giving no precipitate with chloride of mercury, and when 

 boiled with caustic potash and sulphate of copper remaining 

 clear blue. It agrees with albumin and with mucin as I found 



