202 Dv Gairdner's Analysis of 



creatures, and that the body of man himself was, as it were, on- 

 ly an accumulation of such monads ; — as if the aggregation of 

 myriads of these could explain the principle of life itself, — the 

 active moving agent in each individual monad. 



Though, however, philosophers failed in the discovery of what 

 Nature seems to have for ever enveloped in an impenetrable 

 veil, the microscope did not fail to reward their labours by an 

 immense accession to their views of the magnificence of nature. 

 Like the telescope, it gave them a glimpse of a Milky Way of an- 

 other order, equally incommensurate by the powers of numbers. 

 Leeuwenhoeck calculated that, at the very lowest estimate, the 

 milt of a single fish must contain a number of living beings thirty 

 times greater than the whole population of the globe. Dr 

 Ehrenberg himself has described monads which are not larger 

 than from one-thousandth to two-thousandths of a line, and 

 which are separated by intervals not greater than their diameter. 

 Each cubic inch will, therefore, contain more than 800,000 mil- 

 lions of these animalcules, estimating them only to occupy one- 

 fourth of its space; a single drop brought under the field of the 

 microscope, and not exceeding one cubic line in diameter, will 

 contain 500 millions, equal to the whole number of human be- 

 ings on the surface of our globe. Let us only now reflect a 

 moment on the numbers which must be crowded into a stagnant 

 pool or lake, or contained in the vast expanse of the ocean, which 

 the observations of Scoresby have shewn to be equally favour- 

 able to th.cir development, and we will arrive at a result, which 

 leads us to the inevitable conclusion that the mass of organized 

 life is immeasurable. And yet all this is only visible to the 

 armed eye of the naturalist ; but, from its immensity, must play 

 an important part in the economy of nature, and be a subject 

 worthy of the most profound scientific inquiries. 



Every now and then, there are periods which may be consi- 

 dered as epochs in the sciences ; whether from the promulga- 

 tion of some capital discovery, or from the direction they give 

 to the train of future researches. Of such a character, if I mis- 

 take not, are Professor Ehrenberg of Berlin's recent discoveries 

 on the structure and functions of the animals commonly classed 

 under the denomination of Infusoria, to which were referred in 



