446 OF NUTRITION. 



tard its coagulation. Of these, the Sulphate of Soda is stated by Andral to be 

 the best, producing no alteration in the character of the elements, but simply 

 delaying their change of state ; and the following is his account of the appear- 

 ances observed. After a few minutes the blood separates into two parts ; the 

 lower one contains the globules collected together into a soft mass ; the upper 

 one is at first transparent and resembles serum, but soon becomes opaque. At 

 this period a number of globular white corpuscles may be seen in it with the 

 microscope; and these form the first degree of solidification of the fibrin. 

 After 48 hours, the fluid contains numerous flocci like spiders'-webs ; which 

 flocci are chiefly composed of the Fibrin set free from the white corpuscles : 

 this is the second stage of solidification. After 96 hours, the fluid recovers 

 its transparency and contains no trace of separate corpuscles ; but the flocci 

 are more numerous, more firm, and constitute an irregular web composed of 

 fibres arranged in various directions. Where the web is thickest, several 

 reticulated layers may be seen, the one placed over the other ; and in the 

 midst of the distinct fibres, several strings of corpuscles, still retaining their 

 globular character, are perceived. This state of organization is intermediate 

 between that, in which the Corpuscles are altogether separate, and that in 

 which a firm coagulation of the Fibrin takes place ; and it may be seen to be 

 that, through which the buffy coat passes in the progress of its formation 







V. Pathological Changes in the Blood. 



590. From the part which the Blood performs in the ordinary processes of 

 Nutrition, it cannot be doubted that it undergoes important alterations, when 

 these processes take place in an abnormal manner. These alterations must 

 be sometimes the causes, and sometimes the effects, of the morbid phenomena, 

 which constitute what we term the Disease. Thus, when some local cause, 

 affecting the solid tissues of a certain part of the body, produces Inflammation 

 in them, their normal relation to the blood is altered ; the consequence is, that 

 the blood, in passing through them, undergoes a different set of changes from 

 those, for which it is originally adapted ; and thus its own character undergoes 

 a change, which soon becomes evident throughout the whole mass of the cir- 

 culating fluid, and is, in its turn, the cause of morbid phenomena in remote 

 parts of the system. On the other hand, the strong analogy between many 

 Constitutional diseases, and the effects of poisonous agents introduced into the 

 blood, appears clearly to point to the inference, that these diseases are due to 

 the action of some morbific matter, which has been directly introduced into 

 the current of the circulating fluid, and which has affected both its physical 

 and its vital properties.* Here, then, is a wide field for investigation, of 

 which the surface can scarcely be said to be yet broken up, and which must 

 yield an abundant harvest to those who shall cultivate it with intelligence and 

 zeal. The only connected researches which have been yet published, on the 

 changes which the blood undergoes in disease, are those of MM. Andral and 

 Gavarret ;t and these are confined to the alterations which take place in the 



* This doctrine has been recently brought prominently for ward / in a Paper on Sym- 

 metrical Diseases, read by Dr. William Budd before the Medico-Chirurgical Society, 

 Dec. 16, 1841. The Author ingeniously proves, that the symmetry of many diseases 

 (such as certain forms of cutaneous eruptions,' rheumatism, &c.) which do riot imme- 

 diately depend upon external causes, necessarily involves the idea of the conveyance of 

 the morbific agent in the circulating fluid; the palsy produced by lead is a very interest- 

 ing example, in which the agent is known to be mingled with the blood, and to be depo- 

 sited in the parts affected, which are generally, if not always, symmetrical. 



f An account of these inquiries will be found in the Provincial Medical and Surgical 

 Journal for May, June, and July, 1841; in the Annales des Sciences Naturelles, Dec. 

 1840, and March 1841 ; and in the Ann. de Chimie, Tom. Ixxv. They have since been 

 published in a separate form, under the title of "Essai d'Hematologie Pathologique." 



