DR. BEALE^ ON THE TISSUES. 191 



The word living was used in a general sense^ meaning that 

 active changes, some of which can be explained by physics or 

 chemistry, while others cannot, are taking place, or are capa- 

 ble of taking place, under favorable conditions; and by dead 

 was to be understood matter which had already undergone 

 these changes, and which was brought again under- the un- 

 controlled influence of physical and chemical forces. The shaft 

 of a hair, and the particles of the epithelium on the surface 

 of the cuticle, are just as dead before they are detached from 

 the body as afterwards ; but there are constituent elementary 

 parts of every age leading uninterruptedly from these dead 

 particles, which have no power of increase, to those which 

 have only just commenced their existence, which are nearest 

 the vascular surface, and are undergoing rapid multipli- 

 cation. It is as impossible to indicate the precise moment 

 at which a living particle ceases to be able to produce 

 particles like itself, as it is to announce positively the day 

 or hour of our lives when we cease to ascend towards the 

 highest point of vital activity we are to attain, and begin to 

 decline. 



Structure of elementary parts. — Every elementary part con- 

 sists of germinal matter, and of formed material which was 

 once in the state of germinal matter. Just as, in the cuticle 

 on the surface of mucous membranes, and in certain glands, 

 elementary parts exist of every age, so every tissue and organ 

 in the body is composed of elementary parts in every stage of 

 existence, and arrangements exist by which the oldest /ormef/ 

 material may be removed. Some formed material is resolved 

 into simpler compounds, and removed very soon after its for- 

 mation ; while in certain tissues the formed material is very 

 permanent ; and it is doubtful, if, in certain cases, the formed 

 material which now exists in our bodies will not remain in 

 much the same state as long as we live. Most important 

 changes may be brought about by the fluid in contact with 

 this formed material. In health it is bathed with a fluid 

 which preserves its integrity ; but in certain cases the com- 

 position of this fluid is so altered that the formed material 

 undergoes changes closely resembling those which may be in- 

 duced in it artificially, if kept at the temperature of the body, 

 in a fluid which will not protect it from the influence of 

 oxygen. 



Structure of mildew. — If the spore or any segment of the 

 stem of a simple fungus be examined, it will be found to con- 

 sist of an external capsule, inclosing some very transparent 

 matter. The outer capsule is comparatively firm, and hard 

 and unyielding; but the internal substance is soft, perhaps 



