viii 



EDITOR'S INTRODUCTION 



quite impossible, to master the works which 

 appear, almost daily, on various branches of 

 science, or to keep up with the proceedings of 

 our numerous Scientific Societies. 



A distinguished statesman has recently ex- 

 pressed the opinion, that we cannot expect in 

 the next fifty years any advance in science at 

 all comparable to that of the last half-century. 

 Without wishing to dogmatise, I should be dis- 

 posed to hope that in the future the progress of 

 science will be even more rapid. 



In the first place, the number of students 

 is far greater ; in the second, our means of 

 research — the microscope and telescope, the 

 spectroscope, photography, and many other 

 ingenious appliances — -are being added to and 

 rendered more effective year by year ; and, 

 above all, the circle of science is ever widen- 

 ing, so that the farther we advance the more 

 numerous are the problems opening out be- 

 fore us. 



No doubt there are other Scientific Series, 

 but it is not believed that the present will 

 exactly compete with any of them. The 



