SECT. VII.] NECESSITY OF NERVES TO NUTRITION. 423 



which oscillatory motion is the proximate cause of heat.^ 

 Cremadells^ may be also mentioned, who maintained that 

 animal heat is directly generated, kept up, and increased by 

 the vital principle, by which principle he explains all those 

 phenomena of the animal economy, which by others are attri- 

 buted to the nervous system. Schaffer ^ is another writer, who 

 rejecting the doctrine that the cause of animal heat consists in 

 the fermentation of the blood, or in its friction against the 

 sides of the vessels, refers it to a certain vital principle, which 

 is in the nerves. 



Although the doctrine, which teaches that the nerves have 

 a share in the production of animal heat, is not destitute of 

 probability, yet the arguments hitherto advanced do not fully 

 establish it. Perhaps the cause of animal heat is more complex, 

 and cannot be attributed to the nerves only. Undoubtedly 

 there remain many things to be known before we can determine 

 what is the true cause. Especially we ought to wnit and see 

 what the industry of distinguished men may discover"^ respecting 

 inflammable bodies, fire, light, heat in general, and animal heat 

 in especial; taught by these, posterity may be enabled to 

 decide more accurately respecting the cause of animal heat. 



SECTION VII. ARE THE NERVES NECESSARY TO NUTRITION ? 



By the term nutrition, all physiologists understand the con- 

 servation of the body, which is accomplished by the action of 

 certain powers inherent in our body, and which have the power 

 of converting food and drink iuto a fluid, analogous to the 

 constituents of our body, termed the nutritive juice, and thereby 



' Analyse de Fonct. du Syst. Nerv., torn, ii, chap, xviii, xix. Geneve, 1778. 



» Nova Elem. Physiol. Romae, 1779. 



^ Erster Versuch aus der theoretischen Arzneikunde iiber Bewegung und Mischung 

 der Safte. Nurnberg, 1782. 



* Crawford, ' Experiments and Observations on Animal Heat, and the Inflammation 

 of Combustible Bodies.' London, 1779. This little work is reviewed in the Got- 

 tingen Magazine, part v, of the past year. The celebrated Forster also quotes it in 

 a very beautiful article inserted in the same periodical. (See Getting. Magazin, Iten 

 Jahrgangs, 2tes Stiick : *' A theory proposed to explain the cause which occasions 

 the leaves of plants to purify the foul air in sunlight, but to vitiate the air in the 

 shade.") The celebrated Baldinger promises (in the new Magazine) that the illus- 

 trious Landriani is about to give his experiments on light and animal heat. 



