174 THE POPULAR SCIENCE MONTHLY. 



course, it is devoid of symptoms, latent ; the tissue-changes going on 

 do not make known their existence by pain or unpleasant sensations. 

 Did sj)ace permit I might quote without limit from medical authorities 

 to prove not only the occurrence, but the quite frequent occurrence, 

 of orfjanic chauses of structure in their " latent form." The index 

 of almost any text-book on " Pathology," or " Practice," will direct the 

 reader to ample evidence on this point. I will, however, cite one or 

 two well-known authors. Prof. George B. Wood, of Philadelphia, 

 remarks ^ that " sometimes inflammation " (he must refer to sub-acute 

 or chronic inflammation) "runs its accustomed course, so far as relates 

 to its effects upon the textures in which it is seated, with scarcely any 

 of those evidences by which its existence in the interior of the body 

 is usually detected, such as j!?a^/^, disordered function, and constitu- 

 tional disturbance. Under such circumstances it is said to be latent, 

 and often escapes detection." '^ 



Prof. Austin Flint (" Practice of Medicine," pp. 307, 308) refers to 

 cases of what he calls "sj^ontaneous" or "idiopathic endocarditis" 

 (organic modification of the lining membrane of the heart) " which 

 present the physical signs and anatomical characters of the disease icith- 

 out the first symptom having been noticed either hy the patient or his 

 physician,'''^ Tlie terms " latent pleurisy," " latent phthisis," " latent 

 pneumonia," etc., are familiar to every pathologist. With regard to 

 this latter disease I cannot refrain from inserting one other citation 

 from the "Works of Dr. Thomas Addison" [see "New Sydenham So- 

 ciety's Publications," article "Pneumonia," p. 11). Dr. Addison re- 

 marks that Laennec referred to pneumonia xoithout symptoms as of 

 rare but occasional occurrence, and adds : " I am convinced that these 

 reputed deviations and exceptions, regarded as obscure, are of ex- 

 tremely frequent occurrence ; and that they are met with at every 

 period of life, and in every variety of constitution ; and that they are 

 very far indeed from being limited to old persons, or to what have 

 been called complicated cases. . . . Cases with symptoms are in truth 

 themselves the exceptions in a pathological sense ; and, although most 

 frequently met with in practice, are in fact cases of complication." 

 This most apt statement is replete with wisdom, and true to Nature. 

 Truly, the simplest form of the disease, that in which the tissue- 

 changes are gradual (chronic), and without symptoms (latent), is rarely 

 met with in practice, because the pathological evolution has followed 

 so closely its designed course undisturbed, that the physician is never 



' "Practice of Medicine," vol. i., p. 38. 



'^ Dr. Wood, in here using the term " inflammation," is still possessed with the old 

 error (Jong ago set aside by the researches of Dr. Handfield Jones and others), that the 

 growth of fibrous (connective) tissue (the supposed " effect of inflammation upon the 

 textures in which it is seated "), is always due to inflammation. Really this abnormal 

 growth of fibrous tissue is a " new formation," the result of an evolutionary process, and 

 is found after death from inflammation only because it preceded the infiammatory process, 

 and was by this latter brought to a fatal termination. 



