C61 



only by those who have been compelled to unlearn a science that they might 

 at length begin to learn it. 



The technical treatises do less harm, for no one ever reads them except 

 under compulsion. From the establishment of the general equations to the end 

 of the book, every page is full of symbols with indices and suffixes, so that 

 there is not a paragraph of plain English on which the eye may rest. 



Prof. Tait has not adopted either of these methods. He serves up his 

 strong meat for grown men at the beginning of the book, without thinking 

 it necessary to employ the language either of the nursery or of the school ; 

 while for younger students he has carefully boiled down the mathematical 

 elements into the most concentrated form, and has placed the result at the 

 end as a bonne bouche, so that the beginner may take it in all at once, and 

 ruminate upon it at his leisure. 



A considerable part of the book is devoted to the history of thermo- 

 dynamics, and here it is evident that with Prof. Tait the names of the founders 

 of his science call up the ideas, not so much of the scientific documents they 

 have left behind them in our libraries, as of the men themselves, whether he 

 recommends them to our reverence as masters in science, or bids us beware 

 of them as tainted with error. There is no need of a garnish of anecdotes 

 to enliven the dryness of science, for science has enough to do to restrain the 

 strong human nature of the author, who is at no pains to conceal his own 

 idiosyncrasies, or to smooth down the obtrusive antinomies of a vigorous mind 

 into the featureless consistency of a conventional philosopher. 



Thus, in the very first page of the book, he denounces all metaphysical 

 methods of constructing physical science, and especially any d priori decisions 

 as to what may have been or ought to have been. In the second page he 

 does not indeed give us Aristotle's ten categories, but he lays down four of 

 his own : matter, force, position, and motion, to one of which he tells us, 

 " it is evident that every distinct physical conception must be referred," and 

 then before we have finished the page we are assured that heat does not 

 belong to any of these four categories, but to a fifth, called energy. 



This sort of writing, however unlike what we might expect from the con- 

 ventional man of science, is the very thing to rouse the placid reader, and 

 startle his thinking powers into action. 



Prof. Tait next handles the caloric theory, but instead of merely shewing 

 up its weak points and then dismissing it with contempt, he puts fresh life 



