30 Dr. G. O. Rees on a Function of the 



2. A liquor sanguinis containing a large proportion of alka- 

 line phosphate. 



The proof consisted therefore in the examination of these 

 separate parts of the blood. The serum of course would suf- 

 fice for the examination of the liquor sanguinis, as it would 

 contain all the alkaline salts. The clot would serve for the 

 examination of the fats. 



Exp. 1. A quantity of venous blood was obtained from the 

 external jugular vein of a cur dog, and subsequently arterial 

 blood was drawn from the carotid artery of the same animal. 

 These specimens were allowed to coagulate. The serum which 

 separated was in both cases evaporated to dryness, and then 

 incinerated in a platinum dish. Distilled water was poured 

 upon the ashes (which were not completely decarbonized), and 

 the solution so formed poured off" and evaporated. Dilute 

 nitric acid was next added to the dry residues, when lively 

 effervescence occurred in both cases. The acid solution, after 

 being gently warmed, was now tested for phosphoric acid as 

 follows. 



Nitrate of silver was added, which caused an immediate and 

 copious precipitate of chloride of silver. When the solution 

 was no longer affected by the further addition of this reagent, 

 the precipitate was allowed to subside. 



The supernatant clear liquid was next poured off and neu- 

 tralized by the addition of a solution of caustic ammonia; 

 when, in the case of the arterial blood, a plentiful precipitate 

 of the yellow phosphate of silver was observed, while the so- 

 lution obtained from venous blood yielded no evidence of the 

 presence of phosphoric acid, though tested in precisely the same 

 manner. 



Exp. 2. Blood was drawn from the external jugular vein of 

 a cat while under the influence of aether. Half this blood was 

 set aside, the other half was arterialized by exposure over the 

 surface of several dishes. On separately treating the serum 

 of these two portions of blood, and testing them for phosphoric 

 and carbonic acids, as described in Exp. 1, both proved to 

 contain an alkaline carbonate; but the serum from the blood 

 which had not been exposed to air gave no evidence of phos- 

 phate, while that which had been arterialized by exposure 

 yielded a copious precipitate of yellow phosphate of silver on 

 the addition of the nitrate and caustic ammonia. 



Exp. 3. Blood was drawn from the median cephalic vein 

 of a man, the subject of epilepsy. He had dined about half 

 an hour. On coagulation, the serum of this blood was milky, 

 owing to the presence of chyle. I obtained evidence of the 

 existence of an alkaline phosphate in this serum. The car- 



