ACTION OF HEAT AND COLL); THERMOPHILIC BACTERIA. 



247 



('99). SMITH. THEOBAIA The thermal death point 

 of tubercle bacilli in milk and some other 

 fluids. Journal of Experimental Med., vol. 

 iv, 1899. pp. 217-233. Rev. in Central!), f. 

 Bakt., .\.\vin Bd., 1900, p. 409. 



When embedded in the film on the surface of milk, Dr. 

 Smith found the tubercle organism resisted a tempera- 

 ture of 60 C. for an hour. 



(V.y). KASANSKY, M. W. Die Einwirkung der Win- 

 terkalte auf die Pest- und Dip'htheriebacillen. 

 Central!), f. Bakt., xxv Bd., 1899, pp. 122-124. 



These organisms withstood exposure for 6 mouths to 

 severe temperatures. They weie frozen all of the time 

 for the first five months. From December 4 to 28, aud 

 again from February 13 to March 9, the maximum tem- 

 perature was 10 to 234 C, and the minimum was 

 14 to 33.8 C. 



('.,9). LEVIN. See xui. 



('99). MIKONESCO, THEODOR G. Ueber eine besondere 

 Art der Beeinfltissung von Mikroorganis- 

 men durch die Temperatur. Hygien. Rund- 

 schau, Jahrg. ix, 1899, pp. 961-964. Rev. in 

 Centralb. f. Bakt., xxvn Bd., 1900, p. 86. 



('oo). MEYER, J. Ueber Einwirkung fliissiger Luft 

 auf Bakterien. Centralb. f. Bakt., xxvm 

 Bd., 1900, pp. 594-595- 



Anthrax spores and Staphylococcus pyog. aureus were 

 tested. The exposure to the liquid air varied from 5 

 seconds to 15 minutes. Neither organism was killed. 

 The temperature of liquid air is 190 to 220 C .accord- 

 ing to Spiess, and 182 to 192 C. according to Mac- 

 faclyen 



C'oo). SEDGWICK, W. T., AND WINSLOW, C. E. A. 

 Experimental and statistical studies on the 

 influence of cold upon the bacillus of typhoid 

 fever, and its distribution. Jour. Bost. Soc. 

 Med. Sci., vol. iv, No. 7, 1900, pp. 181-182. 

 See also Centralb. f. Bakt., xxvn Bd., 1900, 

 p. 684. 



30 to 60 per cent of the bacilli were destroyed in water 

 during the first hour ot freezing. After exposure for two 

 weeks 99 per cent were destroyed. " The last two or three 

 germs per thousand appear to be very resistant, some 

 remaining a'ter twelve weeks of freezing. The four races 

 used showed constant individual differences in their sus- 

 ceptibility to cold. Alternate freezing aid thawing was 

 tested and found only slightly more destructive than con- 

 tinuous freezing." As several races of typhoid organism 

 were tested, we may infer that ice is not very likely to 

 communicate typhoid fever. 



('oo). PARK, WM. HALLOCK. A few experiments 

 upon the effects of low temperature and 

 freezing on typhoid bacilli. Jour. Bost. Soc. 

 Med. Sci., vol. iv, No. 8, 1900, pp. 213-216. 



Cultures were used from twenty different cases of 

 typhoid fever. They behaved when frozen much as Sedg- 

 wick and Winslow's. On the average, at the end of 

 twelve weeks' freezing only 0.05 of one per cent remained 

 alive, i e. , 1,250 per cubic centimeter as against 2,560,410 

 per cubic centimeter at the beginning. 



"At twelve weeks the bacilli in the ice from nine 

 sources are all dead. Two more show no growth in i cc. 

 The others contain from 80 to 11,000 in each cc. of ice. 

 Only one, however, contains over 1,000 ^culture 9). 

 When typhoid bacilli are in feces, freezing does not 

 exert so much of an effect. Thus typhoid and colon 

 bacilli, originally 37,000 to a loopful of feces, wrre still 

 12,000 at the end of five weeks' exposure to a temperature 

 ranging daily between zero and 28 F. , and typhoid 

 bacilli as well as colon were still abundant in the feces at 

 nine weeks. It is a difficult malterto say for just how 

 long a period ice made from infected water remains dan- 

 gerous. The bacilli, even when few in number, are often 

 vigorous and fully virulent, and, so far as I am aware, we 

 are ignorant as to the number of bacilli required to start 

 infection in man. The longer the infected ice remains 

 frozen the less the number of pathogenic bacteria which 

 remain alive in it." 



Coi). PARK, W. H. Duration of life of typhoid 

 bacilli, derived from twenty different 

 sources, in ice. Abstract of paper read at 

 2d meeting Soc. Am. Bacteriologists, Dec., 



1900, Centralb. f. Bakt., i Abt., Bd. xxix, 



1901, pp. 444-445- 



This describes the completion of an experiment already 

 reported upon in part (see above). At the end of the 

 twenty-second week of exposure the bacilli were dead in 

 all the cultures of each one of the twenty races tested by 

 freezing. 



Coi). D'ARSONVAL. La pression osmotique et son 

 role de defense centre le froid dans la 

 cellule vivante. C. R. des se. de 1'Acad. des 

 sci., Paris, 1901, T. cxxxm, pp. 84-86. 

 The fluid in the bacteria is probably not solidified, if 

 the cell is not ruptured, owing to the enormous osmotic 

 pressure in those small organisms. By lowering the os- 

 motic tension the author thinks that any cell may be 

 killed by cold. 



('02). SCHMIDT-NIELSEN. SIGVAL. Ueber einige psy- 

 chrophile Mikroorganismen und ihr Vor- 

 kommen. Centralb. Bakt., Abt. 2, Bd. ix, 



1902, pp. 145-147. 



(oa). MACFADYEN, ALLEN, AND ROWLAND, SYDNEY. 

 On the suspension of life at low tempera- 

 tures. Abstract of paper read before Sec- 

 tion K of the British Association, Belfast, 

 1902. Annals of Botany, vol. xvi, 1902 pp 

 589-590. 



Various bacterial organisms were exposed from 20 hours 

 to 7 days at 190 C. "These exposures did not produce 

 any appreciable impairment in the vitality of the organ- 

 isms, etc." Also 10 hours at 252 C. the temperature of 

 liquid hydrogen had no appreciable effect on the vitality 

 of the micro-organisms tested. Bacillus typhosus, B.coll- 

 communis, Staphylococcus pyogenes aureus and a Sach- 

 aromycete grew after exposure to liquid air for six 

 mouths. "In no instance could any impairment of the 

 vitality of the organisms be detected." 



The objection to these statements is that quantitative 

 determinations appear not to have been made, at least 

 there is no mention ot any. The writer of this review 

 obtained a decided diminution of the number of viable 

 bacteria in several species by exposure to liquid air for 20 

 hours. 



('02). MACFADYEN, ALLEN. On the influence of the 

 prolonged action of the temperature of 

 liquid air on micro-organisms, and on the 

 effect of mechanical trituration at the tem- 

 perature of liquid air on photogenic bacteria. 

 London, Proc. R. Soc., vol. LXXI, No. 468, 

 Oct., 1902, pp. 76-77. 



" The above experiments show that a prolonged expo- 

 sure of six mouths to a temperature of about 190 C. has 

 no appreciableeffect on the vitality of micro-organisms." 



The organisms tested were H. lyi'ho*ui,Jl. coll corn- 

 munis. Staphylococcu* pynaenes attreus, and a yeast. 

 The triturated bacteria lost their luminosity. 



('05). SMITH AND SWINGLE. See p. 83. 



XXXIV. Thermophilic Bacteria. 



(>9). MIQUEL, P. Title? Bull, de la statistique 



municipale de Paris, Decembre, 1879. 

 Not seen. 



He discovered in the water of the Seine an immobile, 

 rod-shaped Schizomycete capableof living and develop- 

 ing at the temperature of 70 C. 



('81). VAN TIEGHEM, PH. Stir des bacteriacees 

 vivant a la temperature de 74 C. Bull Soc 

 bot. de France, T. 28, 1881, pp. 35-36. 

 This author cultivated several species of thennophilic 

 bacteria at 70 C., and some at higher temperatures. 



C8r). MIQUEI.. Thermobacteria. Annuaire de 1'Ob- 

 servatoire de Montsouris, pour 1881, p. 464. 



