FERMENTATION. 9 1 



and chlorine, or into nitrogen and iodine. Thus a tower 

 made of 2NCI3, or of two large and six small blocks, is trans- 

 formed into two towers, one composed of two large blocks 

 and one of six small ones, or rather into four towers, one 

 composed of the two large blocks and three each composed 

 of two small ones (2NCl3=Nj-|-3 CI,), and along with the 

 falling of these molecules into their lower positions there is 

 a setting free of energy which manifests itself in the form of 

 heat and light. Consider now that in your tower or in your 

 row of bricks you have continual oscillation going on ; the 

 elastic bands are being continually pulled upon by certain 

 forces which we may say are light and heat ; there is continual 

 motion in every part of the tower, or the bricks standing on 

 end are continually oscillating backwards and forwards, but 

 never sufficiently far to disturb the equilibrium completely, 

 when suddenly a third element of disturbance sets in, a small 

 organism comes near and wishes to take out one of the 

 blocks from the tower for its own use ; it seizes the time 

 when the oscillation is greatest, and giving a little extra pull 

 it removes the block, seizes on it firmly and immediately, and 

 the rest of the tower collapses ; or in the case of the swaying 

 bricks, although it has no power alone to upset the first brick 

 in the row, by striking it just when its oscillation is at one 

 extreme phase it assists light or heat, pushes this first sway- 

 ing brick a little further and causes the collapse of the whole 

 line. Bunge gives a series of examples of the breaking down 

 of such chemical substances into simpler materials, and shows 

 how certain ordinary chemical substances along with heat, or 

 even heat alone, may act as fermentation exciters. Thus he 

 points out how a blow can initiate the breaking up of nitro- 

 glycerine into carbonic acid, water, nitrogen, and oxygen. 



Nitro-glycerine is highly unstable, not so much from the 

 elements which it contains as from the method of arrange- 

 ment of the atoms of the elements. Some oxygen has been 

 induced to unite with nitrogen, 'a substance for which under 

 ordinary circumstances it has little affinity, it having at the 

 same time a much stronger affinity for both carbon and 

 hydrogen than these have for one another ; rapid and exten- 

 sive oscillations are constantly going on, the slightest increase 

 of which must be followed by a new arrangement of mole- 

 cules. ''^ A sharp tap so increases these oscillations that the 

 equilibrium of the tower is disturbed, the weak bands between 



