41 8 PHYSICAL GEOGRAPHY. 



with our state surveys, where the gentleman who accepts the position 

 of state geologist is expected to make his investigations practically appli- 

 cable and at an early date, the field of labor is very much more extended, ~ 

 and the assistants required much larger in number. Hence it has come 

 to pass that the modem geologist recognizes the necessity of attaching 

 to his staff of assistants one who is specially skilled in the use of the 

 microscope, an instrument, the proper employment of which necessitates 

 a long and severe schooling of the hand and mind, but more particularly 

 the eye in a peculiar manner and direction. For microscopy has become 

 a science in itself, so that, though the naturalist, the chemist, or the 

 physician may possess and look through microscopes, yet it requires one 

 who has mastered its secrets, and has skilled himself in its most advanta- 

 geous workings, to apply it so as to obtain the best results. But, even in 

 microscopy as a branch of science, there are specialists. Thus, we find 

 one who devotes himself almost exclusively to perfecting the optical por- 

 tions of the instrument ; another will study its application to chemistry 

 and toxicology alone ; another, its use in medicine, pathology, and physi- 

 ology ; another, its employment as an adjunct to geology, and so on, as 

 can be readily understood; for science and knowledge are growing so 

 rapidly nowadays that division of labor becomes as necessary therein as 

 it has been found to be in the mechanic arts. 



These few words, by way of an introduction, have been deemed neces- 

 sary, so that the general reader, into whose hands these volumes may 

 come, might understand that the geological survey of New Hampshire 

 has been the first of our state surveys which has possessed a special 

 microscopist, a person who has turned his attention particularly to the 

 study of the application of that instrument, aided by other means of 

 research, to the investigation of geology. It is true that similar investi- 

 gations have been made to some extent, by others as well as himself, for 

 other surveys ; but in no case hitherto have special collections been made 

 systematically, and in such a manner that any very valuable results have 

 been arrived at, for, in this branch of science as well as in others, a defi- 

 nite end should be had in view, and the specimens collected and the 

 examinations made be for that end. It has remained for the state of 

 New Hampshire to be the first to inaugurate a thorough microscopical 

 survey of its geology and assistant branches of science, — paleontology, 



