1824.] Mr. W. Phillips's Hints to an Edinburgh Reviewer. 285 



many difficulties attend the introduction of two fluids, and so 

 many experiments militate against it, that I would refer to some 

 other cause for an explanation of the fact. 



Every substance which may be used as a conductor possesses 

 a certain quantity of electricity, which, unless disturbed, remains 

 in a dormant or a latent state. When a charge is passed 

 through conductors, I conceive their natural quantity of electri- 

 city is driven offin the same way as water forced through tubes 

 tilled with the same fluid expels the water contained in them 

 before any more can enter; and if an impediment were placed 

 in any part of such tubes, the obstruction would be immediately 

 felt throughout. So with the electrical fluid ; the obstruction 

 made by the introduction of water, which is a less perfect con- 

 ductor than the metals, instantaneously affects the whole line of 

 the circuit in whatever situation the tube may be placed ; and 

 by retarding the velocity with which the electrical fluid moves, 

 prevents the expansive effects which the charge would otherwise 

 have produced. 



I am, Sir, your obedient servant, 



Charles Woodward. 



Article XI. 

 Hints to an Edinburgh Reviewer. By W. Phillips, FLS. &c. 



In the Edinburgh Review for January last, the concluding- 

 article is headed by the title page of the third edition of my 

 Elementary Introduction to Mineralogy ; but the " running 

 title" is, with more propriety, " Mineralogical Systems." At 

 the conclusion of the article, however, the Reviewer has bestowed 

 on my little book half a page ; and though not acquiescing in 

 the correctness of all his observations, I have nothing to object 

 against the tons and manner of the criticism. 



But " there is a circumstance which merits attention, as it 

 affects the degree of confidence which we can place in crystal- 

 lographical indications" (p. 495), as reported by the Reviewer, 

 who proceeds thus : " Similar cleavage planes in different indi- 

 viduals of the same species, meet in some cases under angles of 

 different values. These differences are stated bu the author of 

 the ivork before us, as amounting even to forty minutes of a 

 degree." 



.Now we might expect that a Reviewer should possess the 

 several qualifications essential to the elevated position 

 he voluntarily occupies, when he undertakes the task of 

 criticising the works of others. First, that he should under- 

 stand the subject ; secondly, that he should read the work he 

 criticises; and thirdly, that he should quote faithfully and accu- 



