G. GENERAL NATURAL HISTORY AND ZOOLOGY. 161 



tion to bring forward further arguments, although Dr. Bas- 

 tian does not appear at all satisfied with the reasoning of Dr. 

 Frankland, to judge from the rejoinder he has published in 

 Nature for January 26. 12 A, 1871, Jan. 29, 225. 



THEORY OP ATMOSPHERIC GERMS. 



In a paper on the " Theory of Atmospheric Germs," by Dr. 

 Sansom, published in the April number of the Quarterly Jour- 

 nal of Science, after a critical examination and testing of the 

 various views held by different writers on this question, the 

 author comes to the following conclusions: " 1. Putrefaction, 

 mildew formation, and the appearance of organisms can be 

 checked or absolutely prevented by the existence of certain 

 agents in the air supplied to a putrescible body. 2. The pow- 

 er of such agents can in no sense be measured by their chem- 

 ical constitution and characters. From many experiments, 

 the following expresses their order of efficiency from weakest 

 to strongest : (1), chloride of lime ; (2), sulphurous acid, am- 

 monia, sulphuric ether; (3), chloroform; (4), camphor; (5), 

 iodine, phosphorus, creosote, carbolic acid. 3. The agents 

 which stop fermentation are vegetable, not animal poisons. 

 Fungi will grow in the presence of hydrocyanic acid and of 

 strychnia. 4. Comparative experiments show that a given 

 volatile a^ent is far more efficient when it is contained in the 

 air supplied to a putrescible solution than when an equal 

 quantity is mixed with the solution itself. 5. All fungoid or- 

 ganisms can be prevented by the presence of a minute pro- 

 portion of creosote, carbolic acid, ammonia, hydrochloric acid, 

 or sulphurous acid in the air, though beneath the surface of 

 the fluid are' found numerous bacteria and vibrios. There 

 seems to be no escape from the conclusion that the germs of 

 fungi exist in the air, and are destroyed by the volatile poi- 

 sonous agent." 16 A, 1871, 169. 



ATMOSPHERIC GERMS. 



During a lecture by Professor Tyndall upon dust and smoke, 

 he took occasion to make renewed reference to the influence 

 of atmospheric action upon putrefaction and decomposition, 

 and reiterated his belief that contagious disease is generally 

 of a parasitic nature, and is propagated by spores floating 

 through the atmosphere as positively, to all intents and pur- 



