l64 ROMANCE OF LOW LIFE AMONGST PLANTS. 



generally, without the strictest proof. Observations 

 made with care on isolated individuals, and not on a 

 common mass, which can scarcely be otherwise than 

 more or less heterogeneous, could not fail to be in- 

 structive, and might lead to results which, if they did 

 not confirm the views so commonly entertained in 

 Germany, would have had an influence on science, 

 which it is difficult at present to appreciate.^ 



Ague Plant. 



Early in 1S62 intermittent fever began to show 

 itself in the malarial districts of the Ohio and Missis- 

 sippi Rivers. The disease rapidly increased during the 

 months of July and August, till it had invaded nearly 

 every family on ague levels. Dr. J. H. Salisbury, 

 having previously been engaged in a series of experi- 

 ments on certain plant diseases, came to the conclu- 

 sion that some close investigation might lead to the 

 discovery of the source of intermittent fever in the 

 exhalations of malarial districts. The result of these 

 experiments he recorded in 1866.^ The investigations 

 were commenced by a microscopical examination of 

 the expectorations of those labouring under intermit- 

 tent fever, and who resided upon ague levels, and 

 were exposed during the evening, night, and morning 

 to the cool, heavy, damp exhalations and vapours 

 rising from stagnant pools, swamps, and humid low 

 grounds ; in short, those who were constantly im- 



' Annals a7id Magazine of Natural History ^ZQ..^ 1844), xiv. p. 433. 



^ " On the Cause of Intermittent and Remittent Fevers, etc.," J. H. 

 Salisbury, M.D., in American Journal of Medical Sciences (1866), 

 vol. li, p. 51. 



