788 CYST. 



affords us any facility in distinguishing one difficulties which it must otherwise present, 

 kind of cyst from another, we hold them alike Many accurate observers have expressed a 

 inadequate to lead to correct views of the sub- belief that cysts were a consequence of the 

 ject. The plan which we propose to follow irritation occasioned by a foreign body ; in this 

 may not afford any increased facility in dia- way a large proportion of these organs must 

 gnosis, but it is, we apprehend, founded upon be entirely excluded from consideration, or 

 a more stable basis than either of those to must be treated of under the term acephalocyst. 

 which allusion has been made. We mean to Another class of observers, admitting the exist- 

 consider cysts with reference to the mode of ence of the foregoing, have added another 

 their developement; and although we do not variety: they have assumed that the parietes 

 pretend that this arrangement will afford much of an alveolus of cellular tissue are attacked by 

 greater facility than at present exists for the some " morbid affection " by which all corn- 

 diagnosis of the species, yet it appears to us to munication with the adjoining cells is cut off; 

 be the most natural classification which, in the that the parietes of this alveolus, under the in- 

 present state of our knowledge, we are enabled fluence of irritation, acquire the power of secret- 

 to offer. A considerable assistance in the dia- ing a product entirely different from that which 

 gnosis of these organs may be obtained from they furnish in their natural condition ; that the 

 the adoption of the following principles, which, accumulation of this morbid product causes 

 though not unerring in their application, will a progressive distention of this small cavity, and 

 afford a very near approximation to the truth, a thickening of the cellular laminae in the midst 

 in the majority of cases. Those dysts which of which the tumour is developed : in other 

 are external, subcutaneous, and exactly glo- words, that the tumour so produced acts in 

 bular, with a thinning of the dermis, which the same manner as a shot or other body in- 

 seems to adhere to their surface, commonly troduced from without. In the opinion that 

 contain sebaceous matter of a whitish colour, all cysts are so produced, they are fortified by 

 friable and semi-concrete ; those which occupy the belief that, by the process of maceration, of 

 muscular interstices in the neck, the back, or inflammation, or of suppuration, it is possible 

 the extremities, have, commonly, thin parietes, to reduce the parietes of these organs to their 

 are cellulous, of irregular form, and contain " original element, cellular tissue." Such was 

 either serosity or albuminous pus, in which the opinion of Morgagni, Haller, Louis. The 

 are seen floating opaque flocculent particles ; opinion propagated by Bichat, that a certain 

 those which surround articulations and ten- uniformity in structure obtains in all cysts, 

 dinous sheaths true appendices of synovial that they are all analogous to serous mem- 

 tissues are strengthened externally by fibrous branes, will, it is believed, be found incorrect ; 

 laminae, lined by a serous tissue, and contain a there are many cysts which in structure and 

 more or less pure synovial fluid ; those which function are essentially different from serous 

 ape developed under the anterior annular liga- tissues, for instance, some are fibrous, cartila- 

 ment of the carpus sometimes contain small ginous, osseous, others are cutaneous, others 

 whitish bodies, in appearance not unlike a covered with hair. 



grain of boiled rice ; those which occupy in- Our first class contains the greater number 



ternal cavities, attaching particularly to the of those subcutaneous tumours which are so 



liver, usually contain hydatids, and to the commonly seen under the integuments of the 



ovary contain a variety of products, sometimes cranium, the face, and some other parts of the 



serous, sometimes sanguinolent, sometimes body, and which contain meliceric, athero- 



gelatinous. matous, steatomatous, or other matter. It has 



Until a better method of diagnosis is pre- been over and over again demonstrated that 



sented, the situation of the organ will therefore those follicles which open upon the surface of 



facilitate to some extent the knowledge of its the body may have their aperture obliterated : 



contents. No one, however, will rest satisfied the secretion from the internal surface of the 



with this means, nor underrate the necessity of organ may still proceed, and they occasionally 



pursuing the investigation of these organs, until attain a considerable volume; in this way 



we are in a condition to state with more cer- "steatomatous" tumours are produced. The 



tainty the elements for their diagnosis. matter contained in these tumours has been 



We believe that all cysts may be ranged analysed by Thenard, who obtained the fol- 



underone of the three following categories. A lowing results. 



cyst may be a simple enlargement, or exagge- One hundred parts submitted to desiccation 



rated developement, or other modification of were reduced to forty, which treated by alcohol 



an existing organ. It may be produced by the were, in fact, dissolved : the alcohol in cooling 



irritation excited by the presence of a foreign deposited a fatty matter, which was easily 



body, whether that body be a shot or other melted and was similar to adipocire. The 



substance introduced from without, or a tu- residuum, which formed sixteen parts, was of 



bercle or other abnormal product developed an albuminous nature; consequently there were 



within the body. It may be a new formation twenty-four parts of adipocire. This adipocire 



not before existing in the economy, and pre- did not crystallise like that of the biliary cal- 



existent to the matter which it may be after- culus in man ; it was deposited in flakes like 



vards found to contain. those of putrid animal matter dissolved in 



The last of these categories has not usually alcohol : yet, in the matter of the cyst, it was 



constituted an element in the consideration of in the form of very brilliant micaceous laminae, 



the mode of formation of cysts, and the sub- These cysts frequently appear very thick, but 



ject has in this way been divested of the this great thickness is a consequence of their 



