6 METHODOLOGICAL INTRODUCTION. 



More frequently still, we are obliged to rest content with vague 

 names of disease, unsupported by any history of the case. In most 

 cases certainly the name of the disease is unimportant. It is by 

 no means essential to the scientific comprehension of such enquiries 

 that the whole history of the case from beginning to end should 

 be given with the circumstantiality at present so much in requisi- 

 tion; but we undoubtedly ought to indicate the condition of the 

 patient, as ascertained by a physical examination, at the period of 

 the removal of any morbid product for chemical investigation. It 

 is the practice in reporting chemical investigations, to detail as 

 minutely as possible the method pursued, that the reader may be 

 able to judge for himself, and test the correctness of each individual 

 step. A similar rule should be observed with reference to the state 

 of the disease in all pathologico-chemical investigations, for it is only 

 by these means that we can impart scientific value to such enquiries. 

 We shall find, however, on examining our pathologico-chemical 

 literature, that this principle is too frequently neglected. 



If we would render chemistry truly useful to other departments 

 of natural science, we must be careful to acquire a proper knowledge 

 and a due estimate of the advances made in each ; a point which 

 has unfortunately been too much disregarded in reference to his- 

 tology. We have passed the age when morbid tumours, without 

 regard to their histological constitution, were crushed and pounded 

 in a mortar, with the view of extracting from this artificially pro- 

 duced chaotic mass a principle peculiar to cancer or pus, a scirrhin 

 or a pyin ; but at the present day the combustion tube is still mis- 

 used in the determination of the elementary composition of a mass 

 made up of the most heterogeneous organic parts. Such analyses 

 are wholly devoid of chemical or physiological value, and cannot, as 

 all chemists must allow, in any way contribute to extend the domain 

 of chemistry, while they are useless alike to the physiologist and the 

 pathologist, being utterly devoid of all scientific links of connexion. 

 If, however, w r e take physiology for our guide in such researches, 

 we shall find support from that unity of character to which every 

 scientific enquiry, and every successive experiment should be 

 reduced. 



Pathological tumours afford a good illustration of the extent 

 to which the success of a chemical investigation, and of the method 

 of analysis, depends on a correct physiological view of the question. 

 When we consider the most recent investigations made in relation 

 to this subject, we are led to regard malignant tumours, not as 

 secondary products or parasitic organs, but as exudations which 



