Stance, or parenchyma*, is different in each of them ; this explains their 

 differences, in the double relation of their properties and their uses.- 

 The arteries are not as Ruysch thought, immediately continuous with 

 the excretory ducts, nor are there intermediate glands between those ves- 

 sels, as Malpighi conceived. It seems more probable that each gland 

 has its own peculiar cellular or parenchymatous tissue, in the areolse of 

 which, the*arteries pour the materials of the fluid which the gland pre- 

 pares, in virtue of a power which is inherent to it, and which is its distin- 

 guishing character. The lymphatics and the excretory ducts arise from 

 the parietes of those cells; and these two kinds of vessels absorb; the 

 one set, the secreted fluid which they carry to the reservoirs in which 

 it accumulates, while the other set take up that part of the fluid, on which 

 the organ has not completed its action $ in other words, the residue of 

 secretion. 



XCVIII. Of accidental secretions. If one wished to extend the idea 

 attached to the term secretion, one might say, that every thing, in the 

 living economy is performed by means of the secretions. What is di- 

 gestion, but the separation o'r secretion of the chylous or nutritive parts of 

 aliments, from their faecal or excrementitious portion? Do not the absor- 

 bents concur in this secretion ; may they not be considered as the excre- 

 tory ducts of the digestive organs which acts on the aliment, in the same 

 manner as a secretory gland acts on the blood that contains the materials 

 of the fluid to be elaborated ? Respiration, as we have already seen, is but 

 a double secretion which the lungs perform, on the one hand, of the oxy- 

 gen contained in the atmospherical air, and on the other hand, of the hy- 

 drogen and carbon, of the water, and of the other heterogeneous principles 

 contained in venous blood; and, as will be shown in the ensuing chapter, 

 nutrition is but a peculiar mode of secretion which is different in every or- 

 gan. It is, therefore, only a series of very delicate and very complicated 

 separations and analysis, that the organs are enabled to make extraneous 

 substances undergo such a change of composition, as to render them fit 

 for their grow Hi and reparation. 



There is every reason to believe, that the phenomena of sensation and 

 of motion, by means of which man keeps up, with surrounding objects, 

 the relations necessary to his existence, are the result of the secretions 

 of which the blood furnishes the materials prepared by the brain, by 

 the nerves, by the muscles, Sec. A plant separates from the earth, in 

 which its roots are buried, the juices which it requires; these juices 

 constitute the sap, which, after being filtered through a multitude of ca- 

 nals, supplies the different secretions, whose products are leaves, blos- 

 soms, and fruits, with gums, essential oils, and acids. All organized bo- 

 dies, are, therefore, so many laboratories, in which numerous instruments 

 spontaneously perform various compositions, decompositions, syntheses^ 



* Do the different appearances of the substance of glandular bodies depend on the 

 different manner in which the similar parts cross each other, and on the different pro- 

 portions in every gland ; or do these differences of colour, of density, by means of which 

 we so readily distinguish the substance of the liver from that of the salivary glands* 

 depend on the existence of a peculiar tissue in each organ , ? This question cannot be 

 answered, in the present state of anatomy. The opinion, however, which suppose^ 

 the different nature of the glands to depend on the the different proportions of those> 

 constitutent parts, in each of them appears the most probable. Author's Note 



