REMARKABLi; EFFECT OF EFFLUVIA, &C. 223 



few minutes affected with an uneasy sensation in my eyea, 

 nostrils, throat and lungs, exacting a discharge of tears, 

 sneezing, with running from the nose as in a catarrh, 

 shortness of breath, attended by an itching and heat of 

 the face with sometimes redness of it as from erythema. 

 The last time I was affected, although 1 had not touched 

 the precipitate, I experienced along with the above effects 

 a slight disagreeable taste, and the dyspnoea continued 

 after the catarrhal symptoms had vanished ; which they do 

 usually in about an hour. It may be proper just to 

 mention also, that after -leaving my laboratory for 

 about two hours after the above effects came on, and 

 by which time I was nearly recovered, as soon as 

 I returned to the place where I opened the parcel, but 

 did not again expose myself to it, the above symptoms 

 were again brought on, although in a slight degree. 

 I found wetting my face with cold water very serviceable 

 in removing the erythema, and removing of course the 

 heat. 



I take for granted it is commonly known that by a si- 

 milar exposure to the powder of ipecacuanha root, a fit 

 of asthma is brought on in particular persons, although so 

 rarely that such persons are considered to have what is 

 called idiosyncrasy of constitution. 



The diffusion through the air, manifested in the above ' 



cases of Invisible and imponderable particles of matter, 

 may serve to enable us to conceive the mode in which in- 

 fectious matters are communicated. 

 I am, 



Dear Sir, 

 With much regard, 



An Occas-ional Corfespondeat. 

 Oct. 10th, 1806. 



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