122 Mr. Thomas Richardson on the 



solve the most of this substance. When the hematosine is 

 coagulated it becomes a clotty red mass, which, according 

 as it is heated, exhales a very peculiar odour. 



1. Sulphuric acid dissolves the coagulated hematosine 

 with the application of heat. When evaporated to dryness 

 a neutral compound of sulphuric acid and hematosine is 

 obtained. 



2. The hematosine dissolves in nitric acid with a copious 

 evolution of gaseous fumes, forming a transparent yellow 

 coloured solution. When evaporated to dryness a yellow 

 mass remains very similar to gum, but more viscid than a 

 strong solution of that substance. It has an exceedingly 

 bitter taste. Alcohol partially dissolves it, and leaves a 

 white powder behind. When digested in water all dis- 

 solves except a few drops of an oily matter which floats on 

 the surface. 



Time did not permit me to examine the action of nitric 

 acid upon the hematosine more minutely, but it would ap- 

 pear to be different from its action upon fibrin. 



3. Muriatic acid dissolves the coagulated hematosine 

 very easily, and the solution has a deep-red colour. 

 During the evaporation of this solution to dryness, I ob- 

 served that a white greasy looking substance was formed, 

 with the peculiar odour of burnt cheese. When quite dry 

 this substance had disappeared, but the smell continued. 



4. Caustic soda dissolves the colouring matter, and when 

 the solution is evaporated to dryness what remains has a 

 dark brown or black colour. It is partially soluble in 

 boiling alcohol, and completely in water. The aqueous 

 solution has a yellowish-brown colour. 



5. As Berzelius, and Tiedemann, and Gmelin have ob- 

 served, I found that alcohol dissolves the hematosine in a 

 slight degree. I repeated Berzelius' experiments on this 

 solution and obtained precisely the same results. 



II. THE SERUM. 



The liquid which oozes out from the solid portion after 

 the blood has coagulated, and to which the name of serum 

 has been given, is chiefly composed of albumen. 



It is a transparent greenish-yellow coloured liquid, of a 

 saline flavour and somewhat unctuous to the touch. Its 



