286 On an Apparatus for collecting ['^T^ijl^n'^^t 



III. — On an Apparatus for collecting Atmospheric Particles. 

 By E. L. Maddox, M.D. 



Plate LIV. 



To establish fully any relation between " dust and disease," whether 

 these terms be used in their ordinary or scientific sense, needs an 

 accumulation of evidence which is only likely to be gathered by a 

 multiphcity of observations and experiments, demanding the patient 

 and careful attention of numerous observers, and which, from the 

 minute and varied character of the atmospheric particles, we may 

 expect to long elude our strictest investigations. 



Physicists by a beam of electric light may make known the 

 reality of minute atoms floating in the ordinary air, and heat con- 

 firm the evidence that some at least are organic in theu' nature ; but 

 these two forces by no means prove those particles living germs ; 

 and even suppose they did this, they could not make us acquainted 

 with the genus or species, or prove them carriers of contagion, or 

 whether they were deadly in their natm'e, or simply germs of inno- 

 cuous protophytes, at least so far as we know, as regards ourselves. 



Nor is the question settled by the application of any mode of 

 straining these particles by a cotton sieve. The utihty of cotton 

 in checking their passage has been noted by many observers, and 

 was employed by Drs. Billings and Curtis of the U. S. army, in 

 their experiments related in the valuable Eeport on the Cattle 

 Plague in the United States, published by order of the Commissioner 

 of Agriculture, 1869, Washington ; they confirmed the singular pro- 

 perty of bacteria, vibrios, and molecules, passing through moistened 

 filtering paper, while yeast cells are checked, as pointed out pre- 

 viously by Mitzscherlich, and moreover they marked the impervious- 

 ness to all these bodies, by vegetable parchment, which permits the 

 transit of fluids. 



Dr. Tyndall has shown us that organic matter may escape 

 destruction to a great extent when air is drawn somewhat slowly 

 " over fragments of glass, wetted with concentrated sulphuric acid," 

 also " over fragments of marble, wetted with a strong solution of 

 caustic potash," or when " permitted to bubble through the hquid 

 acid and through the solution of potash," and likewise when rapidly 

 passed through a red-hot platinum tube, containing a roll of pla- 

 tinum gauze. Valuable as these observations are in themselves, we 

 are but little nearer the chief question, which is left open as to the 

 vitality of such organic particles, or their relation to disease. 



Is there then any other plan than that which has been adopted 

 by those who have taken pains to investigate for themselves, which 

 may help forward the solution of this question, at least under one 

 aspect ? It is not sufficient to gather into water the floating germs 



