PROCEEDINGS OF SOCIETIES. 163 



purity, and appear in many cases to arise from the mycelium 

 developed from atmospheric spores. Distinct bacteria are frequently 

 found amongst matter deposited from the moist air of sewers, though 

 almost entirely absent as constituents of common atmospheric dust. 

 The addition of dry dust which has been exposed to tropical heat, to 

 putrescible fluids, is followed by a rapid development of fungi and 

 bacteria, although recognizable specimens of the latter are very rarely 

 to be found in it while dry. Spores and other vegetable cells are 

 certainly present in atmospheric dust, and usually in considerable 

 numbers. The majority of them are living and capable of growth and 

 development. The amount of them present in the air appears to be 

 independent of conditions of velocity and direction of wind, and their 

 numbers are not diminished by moisture. No condition can be traced 

 between the numbers of bacteria and spores, &c., present in the air, 

 and the occurrence of diarrhoea, cholera, ague, or dengue, nor between 

 the presence or abundance of any special form or forms of cells and 

 the prevalence of any of these diseases. The amount of inorganic and 

 amorphous particles and other debris suspended in the atmosphere is 

 dii-ectly dependent on conditions of moisture and of velocity of wind. 

 Dust washed from exposed sm-faces, or collected by gravitation or dew, 

 cannot be depended on. The results of the present experiments are 

 not opposed to the belief in the transmission of these organisms, or 

 other, by means of the atmosphere ; they only refer to bodies 

 distinguishable from one another while in the air ; nothing has been 

 worked out as to their development or action. " What becomes of 

 them," said Dr. Sturt, " when respired ? Is their vitality destroyed ? 

 If so, how are they got rid of? Do they develop within the 

 organism ? Do they then exert any prejudicial influences on the 

 organism ? " These points were not touched upon by the author cited, 

 but he (Dr. Sturt) thought any part of the body they could come into 

 contact with was a secreting or excreting surface, and he could himself 

 see but little chance of their development. 



Dr. Bone, in reply, stated that he had been examining the water in 

 Castlemaine, and that he found organic forms in his own rain-water 

 tank underground, and cemented, and from a clean roof, which he 

 should have thought perfectly pure. He had, however, foimd in it 

 myriads of bacteria, vibriones, and amoebfe, with other minute forms 

 that he did not know, and which presented the appearances of white 

 corpuscles of blood. These, he noticed, while under inspection, split 

 up and divide, having amoebiform movements. He thought that if 

 these organisms passed directly into the air-cells of the lungs they 

 must generate and become a source of poisoning. 



Mr. Sydney Gibbons referred to a paper read at a previous meeting, 

 in which he described these organisms as monadic. 



The Chairman thought these organisms must be taken directly 

 into the system, and in large quantities to cause poisoning effects. 



Mr. Sydney Gibbons gave an outline sketch of the organisms 

 found by him on the bottom of the ' Cerberus,' when docked, besides 

 numerous oysters of a large size, serving to show what could be grown 

 in Hobson's Bay if they were only allowed time for development : 



