OF THE ELEMENTARY SOLIDS. 5 



higher classes of animals, cannot be considered with propriety, to be more than three 

 the celhtlar or laminar, the muscular, and the nervous. 



1st. The cellular fibre is the most essential to animal existence, and is found in every 

 individual of this kingdom. It consists of an assemblage of minute lamina and delicate 

 filaments. It is neither sensible nor irritable, and is chiefly composed of a nearly com- 

 plete gelatine. 



2d. The muscular fibre is not so generally distributed throughout the animal kingdom 

 as the former, for it is not found in the Zoophites. 



3d. The nervous or medullary fibre. The nature of this tissue has been the subject 

 of much investigation. Mr. de Blainville thinks that it originates in the muscular fibre, 

 as this latter takes its origin in the cellular substance. 



To these fibres Professor Chaussier has added a fourth, namely, the albugineous fibre, 

 which is satiny, white, and very strong ; and is neither sensible nor irritable. The ma- 

 jority of anatomists, however, consider it as merely a very condensed variety of the 

 cellular fibre. 



These fibres may be called the first order of solids, as they serve to form all the other 

 tissues and organs of the body. The cellular substance, for instance, is spread out, 

 and condensed into membranes, or rolled up in the form of vessels ; muscular fibres 

 also assume the form of membranes, concur to the formation of vessels, and constitute 

 muscles; nervous fibres produce the nerves, &c. Finally, those primary solids asso- 

 ciate in various forms, and give rise to the compound solids, as the bones, the glands, 

 &c. : and even to those of a more complex nature, as several of the thoracic and ab- 

 dominal viscera. Indeed, every species of solid has for its base cellular substance, 

 which is penetrated by nerves and vessels. The viscera, for example, are of this na- 

 ture, having moreover membranous envelopes. The bones also consist of a similar tex- 

 ture, and of a deposition of phosphate of lime in their cellular substance. (See Ade- 

 lon's Physiol. vol. i. p. 108.) 



Those primary solids, or most simple anatomical constituents which we have just now 

 particularized, associate in various forms, giving rise to compound solids or tissues, which 

 are characterized not only by their form and nature, but also by the functions which 

 they perform. 



These animal textures or compound solids were first arranged with any degree of ac- 

 curacy by Bichat ; and however successful future researches into their ultimate nature 

 may be, or whatever classifications may be proposed by future inquirers, he is still en- 

 titled to the honour of having introduced a philosophical analysis into anatomical and 

 physiological science. The arrangement of the tissues which this great man adopted, 

 is as follows : the exhalent, absorbent, cellular, arterial, venous, nervous of animal life, 

 nervous of organic life, osseous, medullary, cqrtilaginoiis, fibro-cartilaginous. fibrous, mus- 

 cular of animal life, muscular of organic life, mucous, serous, synovial, glandular, dermoid, 

 epidermoid and cor neus or pilous, systems. Mr. Adelon has lately proposed another classifi- 

 cation, possessing some advantages over that of Bichat. He has reduced the number of 

 textures or systems to twelve, viz. the cellular, vascular, nervous, osseous, cartilaginous, 

 fibrous, muscular, erectile, mucous, serous, corneus or epidermoid, and parenchymatoiis. 



Professor Mayer has recently adopted a classification of the animal textures, or com- 

 pound solids, founded on his views respecting the elementary fibres, or primary solids. 

 He recog*nises only seven systems, viz. 1st, the lamellated tissue ; 2d, the cellule-fibrous 

 tissue; 3d, the fibrous system ,- 4>tfi, the cartilaginous tissue : 5th, the osseous tissue ,- 6th, 

 the muscular fibre ; and 7th, the nervous tissue. Jlibliothcyue Geimaniqite. (*/V0. 8. 



The arrangement of this class of solids, which we would propose, is nearlj'the same 

 as that given at another place. (London Medical Repository for July, 1823.) Employ- 

 ing the term tissue generically, we would divide the compound solids of the body into 

 two classes, viz. general systems, and particular textures. 



I. GENERAL SYSTEMS. _Under this class we would arrange, 1st, the cellular system ,- 

 2d, the nervous system, which comprehends two orders, viz. A, the involuntary or gang- 

 lia! order of nerves, or the system of the great sympathetic and K, the voluntary order 

 of nerves; 3d, the muscular system, which also embraces two orders JL, the involuntary 

 order of muscular fibres, and B, the voluntary order of muscular fibres ; 4th, the vascu. 

 lar system .- this system has four orders, viz". A, the arterial order of vessels : B, the 

 capillary order ; C, the venous order ; D, the absorbent vessels, including a, the lym- 

 phatics, and b, the lacteals. 



II. PARTICULAR TEXTURES. This class includes, 1st, the mucous textures ; 3d, serous 

 textures ; Sd, the fibrous textures, embracing the fibrous, the fibro-cartilaginous, and the 

 dermoid ; 4th, the cartilaginous textures , 5th, the osseous textures / 6th s the erectile lex- 



