ZOOLOGY. 367 



Pasteur, from these results, therefore, concludes, that germs sus- 

 pended in the air are the exclusive origin, and the first and necessary 

 condition, of life in infusions, in putrescible bodies, and in liquids 

 capable of undergoing fermentation. 



The generally received theory of ferments, if -we admit the truth of 

 M. Pasteur's conclusions, is furthermore incorrect, inasmuch as a fer- 

 ment is not a dead substance without determinate specific properties, 

 but a being whose germ is derived from the air. It is not, moreover, 

 an albuminous substance altered by oxygen ; but the presence of 

 albuminous matters is an indispensable condition of all fermentation, 

 because the "ferment" depends upon them for its life. They are 

 indispensable in the light of an aliment to the ferment. The contact 

 of the atmospheric air is, primarily, equally an indispensable condi- 

 tion of fermentation ; but it is indispensable only as being a vehicle for 

 the ' germs" of the "ferments" There are, moreover, many distinct 

 organized ferments which excite chemical transformations, varying 

 according to the nature and organization of the ferment. 



The researches of Pasteur also present an interesting field to the 

 naturalist. He has noticed many species in vegetation, new and 

 hitherto unknown. By varying the conditions, it will doubtless be 

 possible to obtain others. On the publication of his (Pasteur's) re- 

 searches, Boussingault called attention to a fact pointed out by 

 Bineau, of Lyons, who, while examining a specimen of rain-water, 

 containing nitrates and ammonia in solution, found these materials 

 disappearing under the influence of cryptogainic vegetation. 



Conclusions of importance to the agriculturist have also been re- 

 cently made known in connection with the above noticed researches. 

 Thus, in order that plants may be developed in atmospheric waters, 

 these waters should be found in the condition of Pasteur's liquids. It 

 is known that rain-water contains assimilable nitrogen and also salts 

 of potash, soda, lime, etc., but it has heretofore lacked the indispensa- 

 ble element, phosphoric acid, which had never been detected in rain- 

 water. This chasm in the series of fertilizing principles of meteoric 

 waters, has at length been filled by Barral, who has discovered phos- 

 phates in rain-water. To avoid all sources of error, this chemist has 

 experimented entirely with an apparatus of platinum. In the resi- 

 due of evaporation he has obtained the phosphorus in the condition 

 of phosphoric acid, as phosphate of bismuth (Chancel's process) and 

 as an ammoniaco-magnesian phosphate. He has thus found a quan- 

 tity of phosphoric acid, varying from .05 to .09 of a milligramme to a 

 litre of rain-water = 0.000.5 to 0.000.9 gram). 



From these results it may be calculated that the rain-water of an 

 ordinary shower furnishes about four hundred gram's of phosphoric 

 acid to the French hectare (or two and one-half English acres). 

 Now, since the researches of Boussingault have proved that a hecto- 

 litre (two and three-quarter bushels) of wheat takes from the soil 

 about one kilogramme of phosphoric acid, we see that to obtain seven 

 or eight hectolitres of wheat to the French hectare, which corresponds 

 to a harvest without the use of manure, it would be necessary to let 

 the field repose for twenty years, if the soil did not previously contain 

 a trace of phosphates. Compiled from Sittiman's Journal. 



