338 Transactions of the Society. 



IX. — On a Portable Form of Aeroscope and Aspirator. 

 By K. L. Maddox, M.D., Hon. F.R.M.S. 



(Bead Uth April, 1883.) 



Seeious attention to the ordinary and morbific conditions of the 

 atmosphere having, at last, gained a place in the study of such 

 causes as may be supposed to originate or accompany zymotic and 

 contagious diseases in their course, I venture to offer to those inter- 

 ested in such studies a portable form of aeroscope and aspirator 

 combined. It was found capable, vrith a single aeroscope, of de- 

 livering 12 to 16 pints of air by the use of one pint of water. For 

 exhibiting it in action, I have adapted two aeroscopes, the air being 

 drawn through each by one trompe or aspirator. To Dr. jMiquel, 

 of the Microscopical Department at the Observatory of Montsouris, 

 in Paris, we are largely indebted for some most interesting articles 

 in the late yearly publications of the ' Annuaire de I'Observatou'e de 

 Montsouris,' on the microbes of the atmosphere, and who, by the 

 continued, laborious, and patient study of the air, dust, water, &c., 

 in different localities, reduced to comparative and statistical data, 

 has been enabled to publish separately, a very enlarged, well-illus- 

 trated and comprehensive work on this most difficult subject.* I am 

 indebted to Dr. Miquel for considerable information about the simplest 

 and best form of trompe, and I have here adopted in a simple way the 

 foiin he has so successfully used. Dr. Miquel writes to me that 

 by carefully proportioning the size and length of tubes, and the 

 inflow of the water, a large delivery of au* can be secured. In his 

 letter he figures a form he employed in the country : a tank holding 

 ten litres of water being suspended from a stout branch of a tree, to 

 which also the asphator is fixed, whilst the aeroscope is placed on 

 a tripod set up at a little distance, the water and air passing from 

 them to another tank on the ground; 10 litres of water sufficing 

 to obtain the passage through the aeroscope of 10 cubic metres of 

 air, delivering from 10 to 11 litres per hour. In the form ex- 

 hibited, the whole is in rather a limited area. The object being to 

 lessen weight and the chance of breakage, bladders are employed as 

 vessels for the water and air collected. 



The description of the double form is given, as from it the 

 arrangement of the single one can be readily deduced. I venture to 

 suggest that the plan could be easily utilized in the wards of hospi- 

 tals, or in the fermenting or other chambers of large breweries when 

 requiring only a temporary or qualitative examination of the air. 



* ' Les Organismea vivants de rAtmosphfere, par P. Miquel, Docteur es 

 Sciences, Docteur en Me'deciiie, Chef du Service Micrograpliique a rObservatoire 

 de Montsouris, Paris, 1883, 308 pp , avec figs. See also infra, p. 403. 



