March 20 , 1883.] 



SCIENCE. 



235 



SCARCITY OF LIVING ORGANISMS IN 

 THE AIR AT HIGH ALTITUDES. 



In the Geneva Archives des sciences for November, 

 1SS4, Mr. Freuderich has an article upon the number 

 of living organisms in the air of the Swiss Alps. He 

 shows that the experiments made by Pasteur in 1800 

 upon the same subject, and later by Tyndall, are 

 unsatisfactory because of the small amount of air 

 filtered, and because it seems, from the results, that 

 the germs were not destroyed from the bouillon which 

 was used in the experiment. Other observers have 

 found astonishing quantities of germs in high alti- 

 tudes, and in all these cases it seems very probable 

 that the liquid was not thoroughly sterilized. 



In Freuderich's experiments, by means of a port- 

 able steam-pump, air was pumped at the rate of a 

 hundred and fifty litres an hour through a small glass 

 tube with a capillary end. This tube was stopped 

 with a wad of spun glass to retain any floating par- 

 ticles. Each wad was then placed entire in the bouil- 

 lon. Later he still further modified this method by 

 using the tube through which the air was pumped as 

 a culture-tube. 



Mr. Freuderich's most reliable experiments were 

 made in the summers of 1883 and 1884. On the 12th 

 of July, 1883, at the height of 3,200 metres, in 300 

 litres of air, no life was found. Again, on Aug. 5, 

 at the height of 2,100 metres, he filtered 500 litres of 

 air, and, on the next day, 400 litres on the summit 

 of a neighboring mountain 3,970 metres high. The 

 filterings from these two were sown in a broth of 

 beef, but showed no signs of life. At Schilthorn 

 (2,972 metres), Aug. 25, 1,500 litres of air were fil- 

 tered and sown, but the fluid did not cease to be 

 limpid. 



In presence of the negative results of 1883, he de- 

 termined not to confine himself in 1884 to the limit of 

 eternal snow, but to choose some places more acces- 

 sible to the germs of the air. On the Aletsch glacier, 

 July 15 and 17, at a height of 2,900 metres, he 

 pumped 2,000 litres of air through six wads. One 

 of the wads, after a rest of fifteen days, gave birth to 

 an organism of the family Tortulacea, and another 

 contained a micrococcus, which may have been ac- 

 cidentally introduced. The second series was carried 

 on above snow-level in Theodule pass (3,340 metres 

 above sea-level) on the 6th and 7th of September. 

 But in 3,000 litres of air he could find but one bac- 

 terium. The extreme poverty of the air at these 

 heights is sufficiently proved by these figures. While 

 these experiments were going on, the days were clear 

 and the wind light, both circumstances favorable to 

 the growth of microbes. 



At Niesen (2,366 metres), July 25 and 26, rain and 

 snow fell, and rendered the work very complicated, 

 soaking the w r ads, and checking the work, so that 

 not more than 600 litres were pumped through eight 

 wads, all of which were sown at Berne, July 27. On 

 July 29 the liquids sown with two of them were in- 

 fested with a peculiar long bacillus, never met with 

 except in the air of Berne; the next day another was 

 infested with the same species; a fourth gave another 



bacillus ; and Aug. 1 a mould appeared. Finally, 

 about the first of September, a last conserve brought 

 forth a mould after six weeks' incubation. The two 

 others remained sterile; and hence we have a mini- 

 mum of four microbes from 600 litres. We say 

 minimum, because it is possible that more than one 

 germ may have been caught on those filters which 

 produced germs. In another trial, July 31 and Aug. 

 1, he filtered 1,725 litres through fifteen wads, in 

 which he found four bacteria. In reducing the re- 

 sults, we find that we have in the air near Niesen 

 between three and four bacteria in a cubic metre. 



The richness of the air in this region is easily ex- 

 plained by the locality, the mountain being situated 

 on the border of Lake Thun, and surrounded by a 

 number of towns. Besides this, a small amount of 

 vegetation is found on its summit. It seems that the 

 purity of the air in these high altitudes is due less 

 to the height than to the lack of a productive home 

 for the growth of these organisms. From these ex- 

 periments it seems perfectly proper to conclude that 

 the mountain air is much purer than that of the 

 lower regions, and even more so than has been sup- 

 posed. Indeed, it is surpassed in purity only by that 

 over the sea, which Commander Moreau has shown 

 to contain only five or six microbes to ten cubic 

 metres. 



RECENT PROGRESS IN ENGINEERING. 



Sir Frederick Beamwell, in his inaugural 

 address as the recently inducted president of the Brit- 

 ish institution of civil engineers, called attention to 

 the great progress made, during late years, in various 

 departments of engineering. Taking up, first, 1he 

 materials of construction, he noted the enormous 

 gain in the economy of brick-making by the intro- 

 duction of brick-making machines and the continu- 

 ous kiln; the improvement taking place in the 

 making of artificial stones now enabling them to be 

 produced with uniformity of quality, and of such 

 durability as to constitute them successful rivals of 

 natural stones. The use of wood is steadily decreas- 

 ing, partly in consequence of its scarcity, and of its 

 unfitness for use where longitudinal stresses are to 

 be encountered, and partly through the introduction 

 of the other materials, which are now made at less 

 cost than formerly. Progress is to be expected in 

 the direction of improved processes for the preser- 

 vation of timber. Asbestos paint, as used on the 

 buildings of the proposed International inventions 

 exhibition, has proved a safeguard in that case 

 against fire. 



The modern processes of steel manufacture are fur- 

 nishing masses of enormous magnitude, and of great 

 uniformity of quality. The processes of Siemens 

 and of Bessemer are now supplying such steels; 

 while the method of Thomas and Gilchrist is per- 

 mitting the use of ores formerly quite inapplicable to 

 such purposes. The cost of cast-iron is decreasing 

 with the construction of larger furnaces, and the 

 use of more highly heated blast, and with a better 

 understanding of the chemistry of the process of 



