682 report — 1884. 



others which might he possibly so utilised. It is even conceivable that animal life 

 could be supported by allotropic or isomeric changes, such as the transformation 

 of amorphous into waxy phosphorous, or of amorphous into crystalline antimony. 



The author then described the chemical changes produced by a large number of 

 micro-organisms, and concluded as follows : — • 



There is no break in the continuity of chemical functions between micro- 

 organisms, and the higher forms of animal life. Both alike owe their vitality to 

 the liberation of the energy stored in their food, and both go through a cycle of 

 existence and then lose their vitality. It is true that there are apparently certain 

 sharp distinctions between them. Thus the enormous fecundity of micro-organisms 

 and their tremendous appetites (on the assumption that all the changed matter 

 passes through their bodies) seem to separate them from the higher orders of 

 animals. But this distinction is only comparative. 



Thus in regard to fecundity, the power of multiplication gradually increases as 

 the animal descends in the scale of organisation. There are, of course, exceptions, but 

 this is the rule. The sheep produces only one or two lambs annually. The herring 

 in the same time multiplies itself many thousandfold, whilst the aphis produces 

 young at such a rate, that a single specimen would, if all its progeny lived, 

 produce in three months a weight of aphides greater than that of the whole con- 

 temporary human race. And, as to appetite, voracity is greatest in the lowest 

 animals. A sheep or cow consumes about one-sixth of its own weight in twenty- 

 four hours ; an earthworm, a caterpillar, or a silkworm, many times its own weight. 

 The yeast organism must therefore, taking into account its position in nature, be 

 considered decidedly abstemious, inasmuch as it only consumes two-thirds of its 

 own weight of sugar in twenty-four hours. Moreover, it must be borne in mind 

 that the sheep converts much of its food into carbonic anhydride, water, and 

 hippuric acid, thus utilising nearly the whole of the potential energy, whilst the 

 micro-organism, as a rule, utilises only a small portion. Further, those micro- 

 organisms which have been chemically studied produce, like the higher animals, 

 perfectly definite chemical changes. There is in this respect, therefore, no essential 

 difference between a mass of yeast, a populous town, a herd of cattle, and a colony 

 of snakes ; each produces its own peculiar chemical changes in the food it consumes, 

 and thereby obtains the energy necessary to its vitality. 



The position of micro-organisms in nature is only just beginning to be appre- 

 ciated. Their study both from chemical and biological points of view is, however, 

 of the highest importance to the welfare of mankind, and I venture to predict that 

 whilst there is no danger of their being spoiled by petting, or by their welfare 

 being made the special care of sentimentalists, these lowly organisms will receive 

 much more attention in the future than they have done in the past. Their study 

 leads the inquirer right into those functions of life which are still shrouded in 

 obscurity. 



2. On Nitrification. By R. Warington. 1 



The Theory of Nitrification.— -Till the commencement of 1877 it was generally 

 supposed that the formation of nitrates from ammonia or nitrogenous organic 

 matter in soils and waters was the result of simple oxidation by the atmosphere. 

 In the case of soil it was imagined that the action of the atmosphere was intensified 

 by the condensation of oxygen in the pores of the soil ; in the case of waters no 

 such assumption was possible. This theory was most unsatisfactory, as neither 

 solutions of pure ammonia, or of any of its salts, could be nitrified in the laboratory 

 by simple exposure to air. The assumed condensation of oxygen in the pores of 

 the soil also proved to be a fiction as soon as it was put by Schloesing to the test of 

 experiment. 



Early in 1877, two French chemists, Messrs. Schloesing and Miintz, published 

 preliminary experiments showing that nitrification in sewage and in soils is the 



1 The original paper will be found in full in Nature, xxx. p. 644. 



