ON THE PRODUCTION OF INFUSORIA. 149 



The results are : 1, a change of colour; 2, a change of consistence ; 

 3. a rising or swelling up of the mass ; 4, a great degree of heat ; 5, the 

 disengagement of foetid fumes ; 6, the evolvement of a combination of 

 gases ; 7, the change of the vegetable substance into a magma or fecu- 

 lent mass ; 8, the drying of the remains into the form of manure, or 

 vegetable mould. 



Second, the required circumstances are: I, maceration in stagnant 

 and unchanged water ; 2, the imperfect access of air by the interposition 

 of the surrounding water ; 3, the loose contact of the stalks or leaves of 

 the vegetables, owing. to their partial diffusion in a fluid medium. 



In all cases of philosophical, and more especially in chemical investi- 

 gation, we are to consider causes and effects: the latter, by the immu- 

 table laws of nature, being the result of the former. If the causes (or 

 circumstances) be precisely the same, the effects will exactly coincide ; 

 but if the effects are different, we must seek for the reason in some 

 alteration or modification of the cause. 



Now, in the present case, the causes or circumstances have been 

 shown to be altered, or modified, and we must therefore expect to find 

 a variation of effects, or a difference in the results. 



Accordingly we find the following effects proceeding from their 

 respective causes : 



CAUSE 1. Maceration in stagnant and unchanged water. 



EFFECT. The effect here is two-fold. 1st, The constant maceration 

 of a vegetable when severed from its root, which is the natural medium 

 by which moisture is received by the plant, cannot conduce to its 

 nourishment, but will sensibly aid its decay, because no circulation can 

 possibly take place ; fresh water would, indeed, produce a temporary 

 revival, but its death and decomposition would ultimately ensue. But 

 here is, 2nd, A water stagnant and unchanged ; and, consequently, not 

 only maceration aids decay, but it is accelerated by the momentarily 

 increasing quantity of decomposed vegetable matter which arises from 

 the process of putrefactive fermentation which is going on. Hence 

 arise the results of gluten, gelatine, and magma ; all of which are to 

 be found in the water, and are the solid parts of the vegetable matter 

 decomposed. 



CAUSE 2. The imperfect access of air, by the interposition of the 

 surrounding water. 



EFFECT. This produces results different from the usual circum- 

 stances. 1, The evaporation of moisture from the mass is prevented, 

 and the water becomes charged in a considerable degree with those 



