Influence of the Component Partsnfthc Soil on Vegetation. 7S 



and were confined for three weeks in this abode, saturated 

 with infection, made to sleep with persons mtccted with 

 the plague, and even dead of it ; and not one were infected, 

 or made ill of the disease. The vapour arising from the de- 

 composition of nitre by the vitriolic acid is perfectly harmless 

 to be breathed, and may be employed in eveiy situation. 

 This was used by] Mr. M'Gregor, after the plan of Dr. 

 Carmichacl Smith, who relates, in ten weeks at Jersey ne 

 lost in putrid fever 50 men from the 88th regiment -, but, 

 beo-inning the fumigation, not only the fever was banishLKi 

 the hospital, but that it changed the nature of the exislnig 

 fever; all the malignant symptoms disappeared, and of 6-4 

 soldiers ill of the fever not one died. 



The subject of air will berenewed infuturecommunications 

 for your excellent magazine, and it is hoped it will rouse the 

 philosophic spirits of more practitioners to the investigation 

 of so interesting an inquiry, which promises the most 

 happy results. In recalling back your readers to the sub- 

 ject vi'i pneumatic medicine, I here solemnly declare that I 

 have no other motive than the good of society, and the 

 extension of science, especially that which so intimately 

 relates to the happiness of mankind. I have the honour 

 to remain. Sir, 



Your obedient faithful servant, 



Robert John Thorntok. 



X. On the Influence of the Component Parts of the Soil on 

 Vegetation. By M. Otto*. 



When the old chemists endeavoured to discover the 

 means by which land could be brought to the greatest pos- 

 sible state of fertility, they imagined that this object could 

 be best discovered by the decomposition of vegetables ; and 

 that, from the kinds of eartii obtained as a residuum, they 

 should be enabled to deduce \\hat kind of plants would 

 thrive best in a certain kind of soil when cnnched with 

 that which is chitfly found in them. That a plant, for ex- 

 ample, which contains a great deal of calcareous earth must 

 thrive in particular in calcareous soil, and that another 

 which contains siliceous earth ought to thrive in a sandy 



601 



11. 



Attempts were made to prove this opinion by experiments, 



* From Aifzdgen der ChurfioitUcb Sachmchen Lnl'Sigcr Oecorivmiscbfn. 

 Scc.CM. ,799. j^„^ 



