228 Du. Buchanan an the White or Opaque Serum of the Blood. 



not occur frequently enough " to be ascribed to that cause. lie ob- 

 served it most " frequently in the blood of breeding women," and 

 therefore conceived it might have some connection with the pregnant 

 state ; but, as he observed it also in other females and in men, he 

 seems to have been at a loss what to think of it, " for/' says he, *' so far 

 as I have been able to observe, it can hardly be said to have any lead- 

 ing cause."* Professor Trail of Edinburgh, has given an excellent ac- 

 count of three cases of a "cream-yellow" state of the serum, apparently 

 connected with inflammation of the kidneys or liver, and he proved the 

 existence in this serum of a fixed oil, as Hewson had done before him. 

 Dr. Trail also first directed attention to a kind of serum like water 

 gruel, in which he could discover no oil. He rejects the idea of the 

 whiteness of the serum proceeding from the food, for that, he says, 

 would have been long since detected. He embraces Hewson's opinion, 

 that it is a pathological phenomenon, and caused by the fat being ab- 

 sorbed " by a diseased action of the vessels." | Dr. Christison seems to 

 regard " lactescent serum'' as a symptom of incipient granular disease 

 of the kidneys. Some eminent modern physicians look upon it as a 

 part of the series of morbid changes in the fluids of the body which 

 occur in diabetes. Dr. Williams, in his recently published *' Principles 

 of Medicine," enumerates milky serum among the diseases of the blood. 

 He thinks it most probably occasioned by an increased absorption of fat, 

 occurring during any rapid diminution of the bulk of the body. Last 

 of all, to conclude this sketch of the prevailing opinions upon this sub- 

 ject, M. Lecanu, who is generally looked upon as the highest conti- 

 nental authority as to the constitution of the blood, enumerates various 

 diseases, of which ** milky blood" is an accompaniment ; he ascribes it, 

 like his predecessors, to an increase of the fatty matter, while he gives 

 as an additional cause, a disappearance of the red globules of the blood. 

 My attention was particularly directed to this appearance of the 

 serum in the year 1840, owing to the frequency with which it pre- 

 sented itself during some experiments I was then engaged in making on 

 the constitution of the blood. I observed with Hunter, that it was of 

 very common occurrence in the blood of young women, who desired to be 

 bled, either because they were, or supposed themselves to be pregnant ; 

 and whom, if no circumstances forbade, it was the custom to gratify in 

 their request. Now, as these young women were for the most part 

 strong and lusty, and therefore likely to take their food well, I was in 

 doubt whether to ascribe thewhitenessof the serum to their peculiar state 

 of body, or to the food which they had probably taken not long before. 

 To resolve these doubts, the most direct mode was to have a person in 

 sound health bled at different periods after a full meal, so as to observe 

 the effects of digestion upon the blood. Accordingly, a strong healthy 

 young man, to whom a good dinner was an equivalent for the loss of a 



♦ On the Blood, 37—39. f Edinb. Med. and Surg. Journal, 1821 and 1823. 



