POUCHET, ON ATMOSPHERIC CORPUSCLES. 261 



of a Horse-chestnut, growing in the garden of the Ecole de 

 Medecine at Rouen, I have counted about thirty grains of 

 wheat-starch, either in the natural or panified condition. 



The search for atmospheric corpuscles in the respiratory- 

 passages is easily made. It consists simply in the passing of 

 a stream of water through these passages, and the collection 

 and examination of the fluid. For this purpose I inject 

 the trachea, by means of a syringe, and when the lungs are 

 distended with water, make incisions into them, and care- 

 fully collect all the fluid that escapes, repeating the injec- 

 tion several times. 



In birds I inject the trachea, and when the water has 

 traversed the lungs and filled all the air-cavities of the 

 body, I open the thoracic cavity, and collect the liquid 

 which escapes in a jet. In all the experiments the fluid is 

 received in conical vessels, with a narrow bottom, and when 

 sufficient time has elapsed to allow all the corpuscles to sub- 

 side these are removed by means of a very slender pipette, 

 and submitted to microscopic examination. The atmo- 

 spheric corpuscles may be collected from the hollow bones 

 by the same mode of procedure. To effect this, I insert the 

 tube of a syringe into the orifice, by which the air pene- 

 trates into the cavity, and then make a section of the bone 

 at the opposite end. The water injected, at first gently, 

 and afterwards with great force, in order to carry along with 

 it the smallest corpuscles, is received in champagne-glasses 

 and examined. Studied in this way, the respiratory organs 

 afford a faithful idea of the life of the animals. Not only 

 does the examination reveal to us what sites of habitation 

 the animals prefer, and their kind of food, but even, when 

 they are domesticated, the profession followed by their 

 owners. 



I have found in the air-passages of man the same atmo- 

 spheric corpuscles as are with met in animals. In the bodies 

 of two persons who died in one of our hospitals, a man and 

 a woman, whose lungs I injected, I found a large quantity 

 of wheat-starch, either normal or panified ; particles of silex 

 and of glass ; fragments of dye-wood, of a beautiful, red 

 colour ; fragments of dress and, lastly, a larva of a micro- 

 scopic arachnidan, still living. 



It was rational to conclude that, at certain times, the 

 expectoration should contain corpuscles similar to those I 

 have described in the lungs. And this is actually the case ; 

 I have here met with normal and panified starch-grains, 

 particles of soot, the debris of plants, filaments of wool or 

 cotton of various colours, particles of silex, &c. 



