570 GENERAL REVIEW OF THE NUTRITIVE PROCESSES. 



very small amount of farinaceous matter 4 being sufficient to cause the re- 

 appearance of the Sugar, after it had seemed to be entirely got rid of. It has 

 been recently proposed by M. Bouchardat to gratify this longing to a certain 

 degree, by allowing the use of bread made of wheaten flour, from which 

 nearly all the Fecula has been separated, the Gluten only being left, with 

 such a small amount of Fecula as may serve to make it rise in fermentation ; 

 so that it is as free from unazotized constituents as the average of animal 

 substances. This plan is stated to have been very successfully practised.* 



716. From what has been stated in Chap. ix. respecting the nature of the 

 Function of Circulation, it is evident that primary disorders of that function 

 are not nearly so frequent as they are ordinarily supposed to be ; and that the 

 proximate cause of morbid phenomena is seldom to be found in them. By 

 the action of the Heart and Blood-vessels, the nutrient fluid, which has been 

 prepared from the alimentary materials submitted to the digestive apparatus, 

 is conveyed to the tissues which it is to nourish ; but the true process of 

 Nutrition is independent of this, and may take place after the motion of the 

 fluid has ceased, just as it commences before any movement shows itself. For 

 the tissue which exists in the Embryo, during the early period of its develop- 

 ment, and also in any newly-forming part, is destitute of vessels, consisting 

 only of cells; and these grow and reproduce themselves at the expense of the 

 nutritive materials supplied to them from without, just as does the whole mass 

 of a Cellular Plant. Moreover it has been shown ( 511), that the activity of 

 the nutrient processes has much to do with the movement of the fluid through 

 the smaller vessels, and is a cause rather than a consequence of it. If the 

 action of the Heart cease, the whole circulation must obviously come to a 

 stand ere long ; but in many animals the Capillary movement may continue 

 for some time after the general circulation has been checked ; and so long as 

 blood is supplied to the parts, so long may their nutrition continue, provided 

 other circumstances be favourable. It is unquestionably true, that the cessa- 

 tion of the Circulation is usually the immediate cause of Death; and that, 

 when the suspension is permanent, the loss of the vitality of the system, con- 

 sidered both as a whole, and as made up of distinct parts, is a necessary 

 consequence. But still, we find that the cause of this cessation seldom origi- 

 nates in the Circulating apparatus itself. Putting aside those forms of Death 

 in which all the vital actions appear to be suspended at once (as in NecrsBmia, 

 592, and in Cooling of the body, 730,) we find the two chief modes to be 

 Syncope and Asphyxia. In the former, the Circulation comes to a stand, 

 simply through want of power in the propelling organs to move the blood ; 

 this want of power may result from a variety of causes. Long-continued 

 deficiency in the quantity or depravation of the quality of the blood may have 

 induced insufficient nutrition of the Heart ; and its muscular power may thus 

 be gradually lost. This is a very common mode of Death, as a sequence of 

 exhausting disease; more commonly, however, the cessation of the Heart's 

 action is sudden, and results from some impression propagated to it through 

 the Nervous system ; thus mental emotion, sudden loss of blood, concussion of 

 the nervous centres, injuries extensively involving the nervous ramifications, 

 &c., seem to have an immediately depressing effect on the Heart's action ; 

 and in many of these cases, the Circulation is checked not merely at the 

 centre but also at the periphery,' the vitality of the system at large, and of 

 the Blood, being equally affected with that of the heart ( 513, 583). The 

 Heart's action may be checked by causes whose action is purely local ; as 

 appears from Mr. Blake's experiments formerly referred to ( 491). But it is 

 probably seldom, in any ordinary condition of the system, that such local 



* See Comptes Rendues de 1'Academie Royale, 1841. 



