79 



Or the system may be under the latent influence of marsh malaria 

 at the time an attack of yellow fever breaks out. This is a compli- 

 cation well calculated to obscure the subject, since these influences 

 may remain dormant in the system for years; British writers say as 

 long as twenty. 



Dr. Kelly* defines yellow fever "a distinct form of continued 

 fever, consisting of a single paroxysm, varying in duration but with- 

 out any true remission." He recognizes a consecutive fever, the 

 result of derangement of the secretory functions — visceral obstruc- 

 tions — chronic inflammation, &c. ; and, therefore, a true epiphenome- 

 non. This has misled writers into describing the fever as intermittent : 

 Dr. Lewis, in the article quoted, maintains that yellow fever may be 

 intermittent, remittent, and continued. 



58. "With regard to the nature of black vomit, Dr. Nott has brought 

 forward strong proof in favour of the opinion, that it is the produc- 

 tion of extravasated blood acted on by an acid, though he has not 

 ascertained what that acid is. As a singular coincidence with this 

 opinion of Dr. Nott, it may be here stated that Dr. Golding Bird 

 attributes the green colour of the stools in infantile diarrhoea to blood 

 extravasated slowly, and acted on by the gaseous and fluid secretions 

 of the bowels, and not to bile.f 



59. As much uncertainty exists as to the causes of yellow fever 

 as any other part of its history. Dr. Nott maintains its animal- 

 cular origin. Dr. Harrison| expresses the opinion that yellow fever 

 is produced by the generation of a poison, which is either in the 

 form of a volatile oil or other organic matter, held in solution by 

 ammonia and floating in the atmosphere. This arises from the ac- 

 cumulation of filth in large cities (chiefly night soil and the animal 

 matter of urine) putrefying under certain meteorological conditions. 

 This is inhaled, and being taken into the circulation, poisons the sys- 

 tem. The meteorological conditions under which it is produced are 

 entirely unknown to us. The effect is as much specific as that of 

 small-pox, scarlatina, &c. It does not depend on putrefaction alone, 

 nor on meteorological influences alone, but on both combined. 



60. Concerning the treatment of yellow fever, we have not found 

 much that is reliable. The recommendations of quinine coming from 



* American Journal of the Medical Sciences, Oct. 1S47. f Lancet, 1S46. 



$ New Orleans Medical and Surgical Journal, March, 1S47. 



