IV PREFACE. 



Much attention has been devoted by the author to the 

 simplification of the instrumental appliances'* in the Experimental 

 Section, so that the student's time may not be needlessly spent 

 in mastering details of machinery, which are not the direct 

 objects of study but only the means to an end. 



The author is indebted to his former demonstrators, 

 W. Gough, B.Sc. Lond., and J. A. Cairns Forsyth, B.Sc. 

 (Hon.) Viet., for repeating many of the processes in the 

 Histological Section, and to his present demonstrator, J. W. 

 Milroy, M.A., M.B., C.M., Edin., for some suggestions in the 

 Chemical Section. 



Existing works have been freely consulted, and acknowledg- 

 ment has been made as far as possible in the context. 



DE BURGH BIRCH. 



YORKSHIRE Co L LEG E , 



LEEDS, April, 18W. 



Carried out mainly l>y A. Kershavv, Kast Donington Street, Leeds. 



