, PREFACE. IX 



management; to remedy this deficiency, the present work 

 has been undertaken. The principal aim the Author has had 

 in view, has been to furnish the uninitiated with a concise and 

 practical account, firstly, of the Microscope as known in 

 former years ; secondly, of the different forms of instruments 

 now generally employed; thirdly, of the methods of applying 

 the same to scientific inquiry; and, lastly, of the various plans 

 of preparing, mounting, and examining animal, vegetable, and 

 mineral substances, together with a classification of a few 

 characteristic and interesting specimens that may be selected 

 from the great volume of Nature. 



It was, at first, the intention of the writer to have included 

 in the present Treatise the methods of dissecting and injecting, 

 as well as many very important matters, purely of an anato- 

 mical nature ; but he' has found it advisable to defer these and 

 all others relating exclusively to physiological science to a 

 separate work, which he hopes at a subsequent period to lay 

 before the medical profession, to whom the Microscope has 

 now become indispensable as an educational instrument. 



The different modes of preparing and examining Micro- 

 scopic objects are chiefly the result of the Author's own expe- 

 rience; but as it would be next to impossible for one individual 

 to be fully conversant with aU these subjects, he begs to state 

 that he will always be glad to receive from fellow-labourers 

 any hints bearing on matters relating to the Microscope, and 

 ready to acknowledge the source from whence such informa- 

 tion may have been derived. In order to render the matters 

 treated of, clear and intelligible to the general reader, as many 

 technicalities as possible have been avoided, and the simplest 

 language made use of; which will account for the plainness of 

 style and composition. 



It may be remarked that the name of Mr. Ross occurs more 

 frequently than that of any other optician; this has arisen 

 from the very valuable papers published by him, from which 

 the Author has made copious extracts; he embraces this 



