The Journal 



OF THE 



Postal Microscopical Society 



JULY, 1883. 



^be application of tbe flIMcroecope to 

 (Bcological IRcaearcb, 



By Mrs. A. Cowen. 



-^^ 



HOUGH the microscope has long been employed in 

 investigations in the growth and development of 

 the lower forms of animal and of vegetable life, as 

 well as in the minute structure of the higher forms, 

 it is only within a comparatively recent period that 

 it has been brought into use by the geological 

 inquirer. In this field a vast amount of informa- 

 tion is afforded by its means, not only with regard 

 to the minute characters of the many animal and 

 vegetable remains which are entombed in the successive strata, of 

 which the crust of the earth is composed, but also with regard to 

 the essential nature and composition of many of those strata 

 themselves. 



The first who conceived the idea of cutting minerals in thin 

 transparent slices for microscopic examination was Nicol, the 

 inventor of the polarising instrument which bears his name. 

 This was in 1827, and in 183 1 his friend, the botanist Witham, 

 studied by this means silicified wood, and proved, to the great 

 astonishment of the learned world, that these stony matters 



G 



