284 FORMATION OF 



proofs as we have that the liver secretes bile, or the testicles 

 semen; we find bile in the ductus hepaticus, semen in the 

 epididymis, and red particles of blood in the lymphatic vessels 

 of the spleen. 



SECT. 104. It may then reasonably be asked, how is the 

 red blood formed when the spleen is taken out, if the spleen 

 is the viscus intended by nature to form the red blood ? This 

 objection will militate equally strong against any other use the 

 spleen is supposed to have ; for that the spleen may be taken 

 out, and the animal suffer but little inconvenience, by no 

 means prove it to be useless, but it proves that some other 

 part is capable of performing its office. Every philosopher 

 must entertain too exalted an idea of nature to believe that 

 any part of the creation is useless, much less could he suppose 

 a viscus in the human body, so large as this is, has no office 

 of importance assigned to it. 



SECT. 105. Suppose, then, for a moment, we allow the spleen 

 to do the office assigned to it by the moderns, viz. that it pro- 

 duces some change on the blood preparatory to the secretion 

 of bile ; what must do that office when the spleen is wanting ? 

 for as the animal lives and is well nourished afterwards, if that 

 supposed change is absolutely necessary for the secretion of 

 bile, either some other viscus must do its office, or the bile, a 

 fluid so requisite for assimilating our food, could not be formed, 

 and the animal for want of being duly nourished must die. 



SECT. 106. If we may reason from analogy, we should say, 

 that it is contrary to the established laws of the animal economy 

 to suppose the use of one organ or gland to be merely sub- 

 servient to another organ or gland in preparing the blood, in 

 order to render it fit for such organ or gland to do its office ; 

 it would be asserting that the liver which nature intended to 

 secrete bile could only do it by the intervention of the spleen ; 

 and yet if we allow that bile can be formed without the use 

 of the spleen,, we admit that intervention to be by no means 

 necessary. But to carry our analogy still farther, nature has 

 given to the animal body certain glands, and has assigned to 

 each peculiar offices, that is, she has endowed them with a 

 property of separating from the blood divers fluids, as different 

 from each other as they are from the mass of blood from out 

 of which they were originally separated. 



