PREFACE. IX 



ing the medical man, materially contributes to the allevia- 

 tion of those multiplied " ills which flesh is heir to." So 

 fully impressed were the Council of the Royal College of 

 Surgeons with the importance of the facts brought to light 

 in a short space of time, that, in 1841, they determined to 

 establish a Professorship of Histology, and to form a col- 

 lection of preparations of the elementary tissues of both 

 animals and vegetables, healthy and morbid, which should 

 illustrate the value of microscopical investigations in 

 physiology and medical science. From that time, histolo- 

 gical anatomy deservedly became an important branch of 

 the education of the medical student. 



In prosecuting the study of Vegetable Physiology, the 

 Microscope is an indispensable instrument ; it empowers 

 the student to trace the earliest forms of vegetable life, 

 and the functions of the different tissues and vessels in 

 plants. Valuable assistance is derived from its agency in 

 the detection of adulterations. In the examination of 

 suspected flour, an article of the greatest importance to 

 all, the Microscope enables us to judge of the size and 

 shape of the starch-grains, their markings, their isolation 

 and agglomeration ; and thus to distinguish the starch- 

 grains of one meal from those of another. It detects these 

 and other " invisible ingredients, whether precipitated in 

 atoms or aggregated in crystals, which adulterate our food, 

 our drink, and our medicines. It displays the lurking 

 poison in the minute crystallisations which its solutions 

 precipitate. It tells the murderer that the blood which 

 stains him is that of his brother, and not of the other life 

 which he pretends to have taken; and as a witness against 

 the criminal, it on one occasion appealed to the very sand 

 on which he trod at midnight" 



The Zoologist finds in the Microscope a necessary co- 

 operator. To the Geologist it reveals, among a multiplicity 



