68 On the Ivflvence of the j4tmo$phere in certain Diseases. 



substance^ : tor in ihe same way as bvdrogen and oxygr. n, 

 the gaseous principle? ot the tornier, niav be reciprocally 

 saturated and form water; in the .same way hydrogen, oxy- 

 gen and azote, the gaseous principles of the latter, may be 

 also reciprocally saturated and form water and ammonia: 

 so that the carbon, which is the only fixed principle which 

 all of them contain, does not pf)s?ess anv propertv relative 

 to that saturation. If we are guided by analogy, we might 

 compare under this point of view ihe animal acids with the 

 vegetable acids, and the animal fats (if there are any which 

 contain azote) with the resins and vegetable oils: conse- 

 quently the hydrogen could not be in a sufFicient quantity 

 in the uric acid, for saturating the oxygen and azote which 

 this acid contains, or to form water and ammonia by 

 combining with these two bodies, and the contrary would 

 take place in the animal fats. A numerous train of con- 

 sequences mav certainly be drawn from all the preceding 

 results; but we shall defer the further consideration of the 

 subject till a future occasion. 



XIV. On the Injixisnce of the Atiriosphere in certain Dis- 

 eases. By Thomas Forster, Esq. 



Sir, An your last Number, yon did me the favour to print 

 some observations on the effects produced, bv varieties in 

 the state of the atmosphere, on M. De Luc's electric co- 

 lumn: allow me to trouble you with some further reflec- 

 tions on this subject, which I request vour insertion of, 

 rather with a view to excite the attention of others to se- 

 veral circumstances connected with this pbaenomenon, 

 than because I think my observations of any value ii> them- 

 selves. 



That a variety of disorders are produced by the influence 

 of the atmosphere is, I btlii ve, verv crenerally admitted : 

 such a supposition is indeed founded on reason ; for if a 

 greal number of persons, at, different places, of divers ages, 

 and of various constitutions and habits of life, become at 

 the same time the subjects of a very similar kind of dis- 

 order, it is rational to"attributc their malady to some general 

 cause then prevailing. The recurrence of suth disonlers at 

 certain times of the year, or on the return of particular kinds 

 of weather, naturally suiicrests an idea that such cause re- 

 sides ia thf air. Ttius, for example, such disorders as are 

 usually called cholera morbus, colica, Sec. usually occur in 

 Augtwttnid September} many persons are subject to cu- 

 taneous 



