344 



SECEETION. 



four to five hours after eating, than during the intervals of 

 digestion ; and he formally advanced the opinion that the 

 spleen serves as a diverticulum for the blood during the pe- 

 riod when there is a great afflux to the digestive organs, and 

 that the extent of its enlargement is in direct ratio to the 

 amount taken into the stomach. 1 Of the accuracy of these 

 experiments there can be no doubt ; " but the second series 

 of observations, in which Dobson attempted to show that 

 large quantities of food cannot be taken with impunity by 

 animals after the spleen has been extirpated, have not been 

 so satisfactorily verified. "We have often removed the spleen 

 from dogs, the operation being followed by complete recov- 

 ery, and have never noted any thing unusual after feeding 

 the animals very largely. In one observation, an animal from 

 which the spleen had been removed six weeks before ate at 

 one time a little more than four pounds of beef-heart, nearly 

 one-fifth of his weight (the dog weighing twenty-two pounds), 

 without suffering the slightest inconvenience. 



Dobson certainly established the fact that the spleen is 

 greatly enlarged in dogs, from four to five hours after feed- 

 ing, that its enlargement is at its maximum at about the 

 fifth hour, and that it gradually diminishes to its original size 

 during the succeeding twelve hours ; but it is not apparent 

 how far this is important or essential to the proper perform- 



1 DOBSON, Structure et fonctions de la rate. Archives generales de medecine, 

 Paris, 1830, tome xxiv., p. 431, et seq. The experiments and conclusions of 

 Dobson are here quoted in full from the original memoir. Gray, who gives in 

 his work upon the spleen a very full resume of the various theories with regard 

 to the functions of the spleen, quotes (page 23) a Gulstonian lecture by Stuke- 

 ley, in 1722, in which the same idea is advanced, though it eeems to be put 

 forward merely as a theory, without any attempt at experimental proof. 

 Hodgkin revived this opinion in 1822, but without presenting any positive 

 proof of its accuracy (HODGKIN, On the Uses of the Spleen. Edinburgh Medi- 

 cal and Surgical Journal, 1822, vol. xviii., p. 90). 



2 The changes in the volume of the spleen have been observed by many 

 physiologists. Bernard noted, in addition, that the blood of the splenic vein is 

 red during abstinence and dark during digestion (Liquides de Vorganisme^ Paris, 

 1859, tome ii., p. 420). 



