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Rafinesque on Atmospheric Dust. 397 
ws 
is sufficient to entitle them to the lasting gratitude of our pro- 
fession. It was one of the merits of that illustrious physician 
of our own time and country, Dr. Rush, that he seized with 
avidity every fact, from whatever quarter it might be drawn, 
to elucidate his favorite science. If ever medicine shall attain 
to the elevation of a truly Philosophical science, it must be ac- 
complished, in part at least, by imitating his example, and by 
developing the infinite and diversified associations which exis 
between it and the other sciences. ss 
Art. XIV. Thoughts on Atmospheric Dust. By C. 8S. Ra- 
FINESQUE, Esq. “: 
lL. 3 W en we find the ruins of ancient cities buried 
under ground; when the plough uncovers the front of pa- 
laces and the summit of old temples, we are astonished: but 
we seldom reflect why they are hidden in the earth. A sort 
ef imperceptible dust falls at all times from the atmosphere, 
and it has covered them during ages.” 
2. These are the words of the worthy and eloquent philo- 
sopher Viney, in his article Nature, Vol. XV. p. 373, of the 
French Dictionary of Natural History. Even before reading 
them I had observed the same phenomena, and I have since 
studied their effects in various places. I could quote a 
thousand instances of the extensive and multifarious operations 
of this meteoric dust: but I mean to give the results merely 
of those that falldaily under notice, and are yet totally neg- 
lected; wishing to draw on them the attention of chemists, 
philosophers, and geologists. 
3. Whenever the sun shines in a dark room, its beams dis- 
play a crowd of lucid dusty molecules of various shapes, 
which were before invisible as the air in which they swim, 
but did exist nevertheless. These form the atmospheric 
dust existing every where in the lower strata of our atmos- 
phere. I have observed it on the top of the highest moun- 
Vol. 1...,.No. 4 , 
