7 1 4 THE POPULAR SCIENCE MONTHLY. 



and accurate perception of an object is gained by bringing it into all 

 its possible relations with our different senses, and so receiving into the 

 idea of it all the impressions which it was fitted to produce upon them 

 it will appear plainly how necessary to true perception, and to sound 

 thought, which is founded on true perception, and to wise conduct, 

 which is founded on sound thought, are thoroughness and sincerity of 

 observation. So to observe Nature as to learn her laws and to obey 

 them, is to observe the commandments of the Lord to do them. Spec- 

 ulative meditations and solitary broodings are the fruitful nurse of 

 delusions and illusions. By faithfully intending the mind to the reali- 

 ties of Nature, as Bacon has it, and by living and working among men 

 in a healthy, sympathetic way, exaggeration of a particular line cf 

 thought or feeling is prevented, and the balance of the faculties best 

 preserved. Notably the best rules for the conduct of life are the fruits 

 of the best observations of men and things ; the achievements of 

 science are no more than the organized gains orderly and methodi- 

 cally arranged of an exact and systematic observation of the various 

 departments of Nature ; the noblest products of the arts are Nature 

 ennobled through human means, the art itself being Nature. There 

 are not two worlds a world of Nature and a world of human nature 

 standing over against one another in a sort of antagonism, but one 

 world of Nature, in the orderly evolution of which human nature has 

 its subordinate part. Delusions and hallucinations may be described 

 as discordant notes in the grand harmony. It should, then, be every 

 man's steadfast aim, as a part of Nature, his patient work, to cultivate 

 such entire sincerity of relations with it, so to think, feel, and act, 

 always in intimate unison with it, to be so completely one with it in 

 life, that when the summons comes to surrender his mortal part to ab- 

 sorption into it, he does so, not fearfully, as to an enemy who has van- 

 quished him, but trustfully, as to a mother who, when the day's task is 

 done, bids him lie down to sleep. Fortniglitly Heview. 



YELLOW FEYER 



By EOGEE S. TRACY, M . D . 



AN attack of yellow fever is generally quite sudden, though in 

 some cases there are slight premonitory symptoms, such as loss 

 of appetite, general uneasiness, headache, or costiveness. It is com- 

 monly ushered in by chilliness, alternating with flushes of heat, or the 

 person may be overcome with languor and extreme debility, while at 

 his usual occupation. These feelings are soon followed by fever, and 

 the bodily temperature rises rapidly, often reaching 102^ Fahr. in a 

 few hours, the normal temperature being 98.4. The fever is accom- 



