ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 403 



of bubbles, by which particles of water are violently thrown into 

 the air. 



Miquel's 'Livicg Organisms of the Atmosphere.'* — Aerial 

 micrography is a study of comparatively recent date, and so beset 

 with difficulties that we hail with pleasure the advent of a work devoted 

 exclusively to the subject, especially from the pen of Dr. Miquel, 

 who for several years, as chief of the micrograj)hic staff at the 

 Observatory of Montsouris, has contributed important articles to the 

 Annuaire de I'Observatoire de Montsouris, Paris. As far as we know 

 it is the only work that embraces comparative seasonal and statistical 

 data. The first attempts of this kind were made we believe in this 

 country by Dr. E. L. Maddox in 1871, who for several months counted, 

 tabulated, cultivated, and figured the air-borne germs entrapped by a 

 self-acting vane or " Aeroconiscope," figured in the Monthly Micro- 

 scopical Journal, June 1870, Owing to the little interest which then 

 existed upon this subject, and the increasing labour it needed, he was 

 obliged to relinquish the study. It was then taken up in a more 

 comprehensive manner in 1872 by Dr, D. Douglas Cunningham of 

 the sanitary service of the Government of India, and the results 

 officially published at Calcutta. The subject has fortunately appeared 

 of such importance to the municipal authorities in Paris, as to lead 

 them to create for it a special department, and they have been most 

 fortunate in selecting Dr. Miquel, who has brought to the task un- 

 tiring energy, skilful manipulative talent, and unbiassed predilections, 

 his sole aim being to arrive by repeated careful observations at some 

 useful data in connection with the floating morbific matter of the air. 

 To attain this object much laborious work is still required. The 

 author now gives us, from his collated researches, a better knowledge 

 of the various microbes to be found in the air, the best method for 

 collecting them and studying their action upon solutions of different 

 materials, and the effect of recognized so-called antiseptics upon the 

 life of the different organisms. 



After sundry trials Dr. M.iquel set up his permanent aeroscope 

 and aspirators at the park of Montsouris, which became the basis for 

 comparisons of the number and kind of microbes found in the air at 

 different localities, the air of sewers, hospitals, cemeteries, and apart- 

 ments, as also that of the laboratory in daily use : and some startling 

 results were obtained. The floating air-dust was collected and ex- 

 amined at every forty-eight hours' interval. A formula was established 

 for counting the number of spores, &c., found in a given space on the 

 surface of the glass that retained them, and corrected for the quantity 

 of air drawn through the aeroscope in a given time. The dusts that 

 had settled in undisturbed places, in apartments, in the laboratory, 

 &c., were examined and contrasted. The infective powers of the soil 

 and of the waters of the Seine and of sewers were compared, and 

 lastly a method of fractional cultivation in certain special sterilized 

 liquids or broths was adopted. The experiments have accumulated 



* Miquel, P., ' Les Organismes vivants de I'Atmosphere,' Paris, 1883, 308 pp. 

 and numerous figs. 



2 D 2 



