MORBID STRUCTURES, ETC. 141 



It was at one time " fondly hoped" (says Dr. McClellan), 

 " that by the aid of powerful microscopes we could be able to 

 detect the pre-existing germs of all organic diseases in the 

 general circulation, and decide not only as to the species of 

 affection, but also concerning the degree of constitutional con- 

 tamination. It was even thought that cancers could thus be 

 distinguished from scrofula and all other more innocent dis- 

 eases; while, at the same time, we could form a conclusive 

 opinion as to the propriety of attempting or declining a sur- 

 gical operation, or of instituting any mode of local treatment 

 for the purpose of affording relief. But all such attempts have 

 proved to be illusory, and we can gather no other practical 

 knowledge from the use of the microscope than what is con- 

 nected with the minute anatomy of the morbid structures after 

 they have been elaborated." With all deference to the opinion 

 of so truly a great mind as the lamented McClellan, we may be 

 permitted to remark, that notwithstanding much has been done 

 by the labors of .European and other observers, minute patho- 

 logical observation is still in its infancy; yet it has made a 

 deep impression upon the study of medical science. When 

 " the minute anatomy of the morbid structures" shall be fully 

 known, our knowledge of organic diseases will have advanced 

 to a great degree of perfection. Dr. McClellan is not himself 

 insensible of the advantages to be derived from microscopic in- 

 vestigations, although we think he places too little value upon 

 them. He says, " Chemical analyses and microscopic re- 

 searches have lately proved that a great number of cases (of 

 tumors) which were once thought to be scirrhous, or cartila- 

 ginous, or osteo-sarcomatous, are really composed of condensed 

 fibrine of the blood, sometimes partially altered into albumen 

 or gelatin." 



The microscopic appearance of a fibrous tumor is exhibited 

 in Fig. 43 (after Yogel). It shows interlacing fibres, C. Pri- 



