BLOOD, MORBID CONDITIONS OF THE. 



427 



clusively that the albumen of the blood will 

 be found deficient in proportion. In other 

 dropsical affections it will sometimes happen 

 that a proportion of albumen more than equi- 

 valent to the fibrine effused will disappear 

 from the circulation. Eleven days after tap- 

 ping a young woman, in whom ascites had 

 supervened upon rheumatic affection of the 

 heart, she was observed to be filling again very 

 fast. A few ounces of blood were taken from 

 the arm, and this blood was found to contain 

 0'319 per cent, of fibrine, and only 3'51 per 

 cent, of albumen. Her serum had a specific 

 gravity of 1-023. 



The experiments of MM. Prevost and Dumas 

 (Annales de Chimie, vol. xxiii.) which have 

 since been repeated by Gmelin and Tiedemann 

 (PoggendorfFs Annalen), prove satisfactorily 

 that urea exists in the blood after the kidneys 

 have been extirpated, and consequently that it 

 is not formed, but merely abstracted by those 

 organs. So long, however, as the kidneys act, 

 we cannot expect to find it, since it is removed 

 from the circulation as fast as it is formed, and 

 never exists in any considerable quantity. 



In these cases of diseased kidney a result 

 analogous to that which follows extirpation 

 occurs, for while that organ is permitting albu- 

 men to pass through it unchanged, the urea 

 which it should separate is very generally if not 

 always found in the blood. This I have proved 

 in repeated instances, and it is now so generally 

 admitted from the experiments of Prout, Chris- 

 tison, and others, that it is scarcely worth while 

 to cite cases. Dr. Bright, vol. ii. p. 447, al- 

 ludes to several specimens of serum from 

 patients under this disease, which he had sent 

 me for examination, in some of which I did, 

 and in others I could not detect urea. In one 

 very remarkable instance of a young woman, the 

 albuminous state of whose urine constantly 

 existed for above three years, the urine con- 

 tained less than one-third of the normal pro- 

 portion of urea, while about one per cent, of 

 albumen supplied the deficiency. The serum 

 of the blood was, as I have already remarked to 

 be usual in this disease, of very low specific 

 gravity, being only 1-021. The quantity of al- 

 bumen in 1000 grains amounted, after careful 

 drying, to only 50 grains instead of 78 (Le- 

 canu's healthy standard), and it contained fully 

 as much urea as the urine itself, the 1000 grains 

 yielding nearly 15 grains of that principle. 



It may not be out of place here to observe, 

 that in this disease not only does the blood it- 

 self contain urea, but all those effusions also 

 which are formed from it, and which take place 

 in the different serous cavities. I have repeat- 

 edly detected urea in these cases in the serous 

 effusion into the ventricles of the brain ; and 

 Dr. Barlow found it in one case, 1st, in abun- 

 dance in the ventricles of the brain ; 2dly, 

 scantily in the effusion into the pleura and peri- 

 cardium ; and 3dly, in ^abundance in the peri- 

 toneum. In a second case of a similar nature 

 urea was obtained in abundance from the fluid 

 of the pericardium. In a third the effusion 

 collected after death from the pleura of a man 

 who had suffered from general dropsy and mot- 



tled kidney, yielded a very satisfactory specimen 

 of urea. 



I have dwelt at some length on this subject, 

 as it is only of late years that the attention of 

 the medical world has been drawn to it through 

 the writings of Dr. Bright, and still more re- 

 cently that the morbid changes presented in the 

 blood have been investigated. 



Diabetes. In this complaint the blood un- 

 questionably undergoes some material change, 

 although its nature has not hitherto been very 

 successfully investigated. This may be inferred 

 from the great length of time during which it is 

 capable of resisting putrefaction, a circumstance 

 first noticed by Hollo, and which, though 

 doubted by some authors, I have had oppor- 

 tunities of confirming in several instances. 

 Nicolas and Gieudeville* have observed that it 

 contains an increase of serum and very little 

 fibrine, but this is not borne out by my own 

 experience as deduced from many specimens of 

 diabetic blood which I have examined; neither 

 can its antiseptic qualities be attributed to any 

 deficiency in the proportion of azote, for Dr. 

 Prout, who has made accurate experiments to 

 determine this point, has found it not to differ 

 in this respect from the standard of health. 

 The most eminent chemists both abroad and in 

 this country have endeavoured in vain to de- 

 tect sugar in diabetic blood. Dr. Wollaston 

 ascertained that the smallest portion of saccha- 

 rine matter added to serum previously to its 

 coagulation by heat, prevents the subsequent 

 crystallization of the salts it contains, yet that 

 in diabetic serum those salts crystallized with 

 the same facility as in that procured from a 

 person in health. The same reasoning as that 

 which has been adduced to prove that urea may 

 be formed in the blood, although it is not to be 

 detected there while the kidneys perform their 

 office, will also apply to the existence of sugar 

 in the blood of those affected with this disease. 

 I am not aware that the arterial blood has been 

 made the subject of experiment, and yet it is 

 possible that it might exist in the arteries alone, 

 for we have only to suppose it to enter the cir- 

 culation with the chyle, and after having been 

 carried through the lungs, the left cavities of the 

 heart, and the aorta, to be again withdrawn from 

 the circulation by the kidneys. I do not pre- 

 tend, however, that this supposition carries with 

 it any degree of probability. 



Cholera. There is no disease in which the 

 blood undergoes more remarkable changes than 

 in malignant cholera; not indeed in the in- 

 cipient stage, as affirmed by Dr. Stevens, but in 

 direct proportion to the intensity and duration 

 of the collapse. In appearance it is thick and 

 dark, bearing a strong resemblance to treacle or 

 tar. It is of high specific gravity, the serum 

 varying from 1-040 to 1-045 at 60 Fahr.; and 

 according to M. Lecanu, the solid matter which 

 it contains is sometimes double that of the 

 healthy proportion. Most of its physical cha- 

 racters are satisfactorily accounted for by its 

 analysis, which has been accurately made by 

 several eminent chemists, among whom we may 



* Annales de Chimie, vol. xliv. p. 69. 



