166 Dunglison^s Human Physiology. 



its doctrines susceptible of demonstration, this would be the only cor- 

 rect plan of placing it before the public. Unfortunately, however, 

 such is the nature of this science, so obscure are many of the func- 

 tions of the animal fabric, so minute are many of its parts and so 

 mysteriously, in the present state of our knowledge, do they perform 

 their important operations ; and at the same time so prone is the hu- 

 man mind, over confident in its own powers, to erect general princi- 

 ples upon insufficient and insecure foundations, that many of the lead- 

 ing doctrines of physiology instead of being supported by demon- 

 stration are still matters of dispute ; others maintain their credit rath- 

 er by the authority derived from the name of their author, than by 

 the strength of their supporting facts ; and others still, are mere the- 

 oretical notions, with little either of fact or authority to uphold them. 



This is essentially the plan of the justly esteemed work of Pro- 

 fessor Blumenbach, the latest edition of which, translated into Eng- 

 lish and much enlarged, and brought down to the present time, by 

 Dr. Elliotson, of London, contains a greater amount of truth, briefly 

 yet plainly stated, with a smaller admixture of error, than any other 

 similar treatise in the language. A reprint of this work in this coun- 

 try would be a valuable addition to its medical literature. 



Under these circumstances many, perhaps most authors have 

 adopted a different plan. This consists, for the most part, in a state- 

 ment of all the known facts, or a selection of the most important of 

 them, upon the several branches of the subject ; in arranging them 

 under heads corresponding with the systems of which the body is 

 composed, and in deducing from them such doctrines, as in the au- 

 thor's view, they support. This plan, while it demands a minute and 

 sometimes tedious detail of facts, and while it carries with it little of 

 the air of a well arranged and established science, yet has many ad- 

 vantages. Especially, a more perfect opportunity is afforded to the 

 reader, by the full display of facts, to judge of the soundness of the 

 principles laid down, to correct those which are erroneous, and to 

 form and establish others more correspondent to the truth. Even 

 here, however, with all the facts before him, there is much to perplex 

 the student of this interesting and important science. The rnixture 

 of truth and error, which he has not sufficient knowledge to distin- 

 guish and separate ; the devious paths, struck out by ingenuity, lead- 

 ing to self display, rather than to simple truth, and sometimes the ob- 

 vious sophistry employed to establish some favorite fallacy, embar- 

 rass and bewilder his mind. A work which should be free, in a great 



