312 BECORD OF CURRENT RESEARCHES RELATING TO 



5. The presence of bacterial germs was in some cases proved in 

 air absorbed from the soil. 



6. The air, on the other hand, from the typhus-ward of a hospital 

 was found to be free from living bacterial germs, probably in conse- 

 quence of ventilation and disinfection. 



7. The air from a sewer was rich in such germs. 



8. The number of these experiments was not sufficient to determine 

 whether the diiference between bacteria collected from the air in 

 different places, and especially in certain localities, has any patho- 

 genous significance, the results at present being negative. 



Bacteria and Insect-Larvae.*— Mr. J. J. Friedrich finds that 

 septic liquids containing putrid meat and decaying plants were 

 piu'ified after the larvte of Culex pipiens had developed in them and 

 feasted upon the myriads of bacteria, &c. The liquids became per- 

 fectly clear, transparent, and odourless, the bacteria at the same time 

 disappearing entirely, and he considers that he has established that 

 the larvfe of Culex and other insects are the most important factors 

 for controlling and preventing septic processes. 



Destruction of Insect Pests by means of Fungi. — Cf. p. 246. 



Septic Organisms in Living Tissues.t— In 1874 Professor Tiegel 

 undertook experiments to decide whether sejitic organisms exist in the 

 living tissues. He sealed up parts of the bodies of newly-killed 

 rabbits by dropping them into melted paraffin at a temperature assumed 

 to be high enough to destroy any infection in transit from the ani- 

 mal's body to the paraffin. He found that in most instances the 

 unheated centre of the flesh became in a few days putrid and swarming 

 with bacteria.^ Dr. Burden Sanderson repeated these experiments § 

 with the result of always finding bacteria. On the other hand Chiene 

 and Cossar Ewart,[| using the additional precaution of antiseptic 

 spray, came to a very different conclusion. 



In the winter of 1875, Staflf-Surgeon E. L. Moss, E.N., sealed up 

 musk-ox meat in clean Arctic air, and it remained perfectly fresh until 

 the glass tube containing it was accidentally broken thirteen months 

 afterwards. Any sources of putrefaction which may have existed 

 were possibly, he thinks, destroyed by the low temperature to which 

 it had been exposed. 



Mr. Moss subsequently made some experiments to try whether flesh 

 would keep equally well if removed warm from the body of a recently 

 killed animal, and simply sealed in an atmosphere whose freedom from 

 life could be guaranteed. He led a pipe from the nozzle of a well- 

 weighted blacksmith's bellows, through a tube of hard glass 6 feet long 

 packed with platinum foil, and heated to redness in a Hoffmann com- 

 bustion furnace, thus obtaining a sti'eam of air at the rate of 70 cubic 

 feet an hour at a temperature of between 380^ and 420^ Fahr. This 

 current was cooled to between 70° and 80° by passing through a brass 



* ' Am. Journ. Mier.,' v. (1880) p. 34, from ' Medical Record.' 



t ' Kep. Brit. Assoc.,' 1879, p. 416. % Virchow's ' Arcbiv.,' xvi. p. 453. 



§ 'Brit. Med. Journ.,' 1878. || 'Journ. Anat. and Physiol.,' 1873. 



