296 



first, tincture of rhubarb was given, to the quantity of a pint and a 

 half in three doses of half a pint each, with the same quantity of 

 water. The fourth and fifth had powdered rhubarb made into a 

 bolus, and the sixth took three pints of infusion of rhubarb. 



When the asses were killed, equal quantities of blood were taken 

 from the splenic vein and from the left auricle of the heart, or from 

 the vena cava, and suffered to coagulate, that the serum of each 

 might be obtained for examination by alkalies, in comparison with 

 each other, and with the urine of the animal, as well as with infu- 

 sions of its spleen and of its liver in water. 



In the first of the experiments Avith tincture of rhubarb, the infu- 

 sion of the spleen had a tint of colour equal in intensity to that of' 

 sixty drops of tincture of rhubarb in two ounces of water; the 

 serum from the blood of the splenic vein, to fifteen drops ; the serum 

 from the auricle, to three drops. The urine had so deep a tinge that 

 it nearly resembled the pure tincture itself. 



In the second and third experiments the results were nearly simi- 

 lar, but less intense. But in those asses to which the rhubarb boluses 

 had been given without any fluid, the spleen was found in its con- 

 tracted state, with cells scarcely visible, and without sensible impreg- 

 nation by the rhubarb ; but the caecum and colon contained several 

 quarts of fluid, in which the rhubarb was more evident both to sight 

 and smell than in the stomach. The urine also was highly impreg- 

 nated with the colour of the rhubarb. The effects from infusion of 

 rhubarb were perfectly similar to those from the tincture, but the 

 colours occasioned by it were not so intense. 



In the course of these experiments, an attempt was made to ascer- 

 tain whether the blood from the splenic vein contained more serum 

 than that from other parts of the body ; but the difference observable 

 was not so great as it was afterwards found might be occasioned by 

 other circumstances. 



From the experiments contained in his former and present paper, 

 Mr. Home considers it ascertained that the spleen is sometimes 

 found distended to double the bulk which it occupies in its more 

 contracted state. 



In the distended state there is a cellular structure distinctly visible, 

 but in the contracted state these cells cannot be seen without a mag- 

 iiifying-glass ; the difference between these states depending upon 

 the quantity of liquid that was contained in the stomach before death. 



If the fluids contained in the stomach be coloured with tincture of 

 rhubarb, the spleen and the blood in the splenic vein are coloured 

 also, more strongly than the liver or blood contained in other 

 veins of the body ; so that the colour cannot arrive at the splec ir > 

 through the ordinary course of the circulation. But when the sto- 

 mach is kept without liquids, although the colouring matter be car- 

 ried through the system to the urine by the ordinary channel, no 

 particular evidence of it is to be met with in the spleen or its vessels ; 

 but the principal absorption takes place from the caecum and colon. 

 NO vessels, however, have been discovered by which the communica- 



