1 835.] of the Distillation of Pit Coal. 55 



restores the blue tint. Neither alcohol, ether, nor eupion 

 dissolve it. Acetate of lead, salts of tin, ammonia, sulphate 

 of copper, and acetate of alumina, precipitate it blue, which 

 is not changed by an excess of ammonia. Pittacal is 

 therefore useful as a dye-stuff. It fastens on cotton and 

 linen very well with alumina and salts of tin. 



Article IX. 



On the acid nature of the Blood, and the distinction between 

 Arterial and Veinous Blood. By R. Hermann. (Bog- 

 gendorff's Ann. xxxi.J 



Three years ago the author announced that he had dis- 

 covered acid in the blood, but his position was not admitted 

 by any chemist. In 1833, he took advantage of the pre- 

 sence of Dr. Stevens in Moscow to repeat his experiments. 

 He found 1 . That neutral tincture of litmus was coloured 

 red by veinous blood taken from the arm of a healthy Rus- 

 sian aged 31 years. 



2. The coagulum being rubbed up with distilled water 

 boiled, and the solution containing the salts concentrated, 

 the residue did not alter tumeric, and had a doubtful effect 

 upon litmus paper. 



3. 720 Gran of veinous blood fresh from the arm, were 

 heated with a solution of muriate of lime in a pneumatic 

 apparatus, and the gas extricated was collected over mer- 

 cury. Potash absorbed, \ Russian cubic inch carbonic acid. 



6. Veinous blood was coagulated at a high temperature, 

 and the coagulum boiled with water and evaporated. The 

 concentrated residue exhibited an acid nature to tincture of 

 litmus, and to red litmus paper rendered red, an alkaline 

 state. On examination, he discovered that the distilled 

 water employed, contained phosphate of soda, and observed 

 that he could produce this paradox, by adding to phosphate 

 of soda some acetic acid. As the neutral phosphate of soda 

 has an alkaline effect upon vegetable colours, he conceives 

 that the acid re-action of the blood is to be attributed to the 

 presence of acetic acid. 



6. Tincture of litmus mixed with fresh serum, was ren- 

 dered red. Red litmus paper became blue in the same 



