FUNDAMENTAL PRINCIPLES OF DISEASE. 



By Rush Shiimm;n Hiidkkoi-kk, .M. I >.. \'kt. 



[Revlsod by I Hi>nl I'.iusDn, 1'.. S., V. M. !».] 



ANIMAL TISSUES. 



Tho nonprofessional reader may repinl the animal tissues, which 

 are subject to inflanunation, as excessively simple structures, as simi- 

 lar, simple, and fixed in their organization as the joists and boards 

 ■which frame a house, the bricks and iron coils of pipe which build a 

 furnace, or the stones and mortar which make the support of a great 

 railroad bridge. Yet while the principles of structure are thus sim- 

 ple, for the general understanding by the student who begins their 

 study the complete appreciation of the shades of variation, which 

 differentiate one tissue from another, which define a sound tendon or 

 a ligament from a fibrous band — the result of disease filling in an old 

 lesion and tying one organ with another — is as complicated as the 

 nicest jointing of Chinese woodwork, the building of a furnace for 

 the most difficult chemical analysis, or the construction of a bridge 

 which Avill stand for ages and resist any force or weight. 



All tissues are composed of certain fundamental and similar ele- 

 ments which are governed by the same rules of life, though at fii-st 

 glance they may appear to be widely different. These are (a) amor- 

 phous substances, (b) fibers, and (r) cells. 



(a) Amorphous substances may be in licjuid form, as in the fluid 

 of the blood, which holds a vast amount of salts and nutritive matter 

 in solution; or they may be in a semilicjuid condition, as the plasnui 

 which intiltrates the loose meshes of connecti\e tissue and lubricates 

 the surface of some membranes; or they may be in the form of a glue 

 or cement, fastening one structure to another, as a tendon or nuiscle 

 end to a Ijone; or, again, they hold similar elements firmly together, 

 as in bone, where they form a still" matrix wlijcli becomes impreg- 

 nated with lime siilts. Amori)hous substances, again, form the pro- 

 toplasm or nutritive element of cells or the elements of life. 



(b) Fibei's are formed of elements of organic matter which have 

 only a passive function. They can be assimilated to little strings, or 

 cords, tangled one with another like a mass of waste yarn, woven 

 regularly like a cloth, or bound together like a rope. They are of two 



