Correction in the Applications of the Electric Column. 1 1 



extensive observation of individuals, whether particular organi- 

 zation of the brain were exempt from any of the calamities of 

 constitutional diatheses; but have found no relation between 

 the two circumstances. I have seen heads of various kinds in 

 persons of all the various temperaments and constitutional dis- 

 eases, and the faculties of their minds seemed modified by these 

 circumstances of constitution. Sometimes, indeed, there are 

 exceptions to this rule, wherein \\c find extraordinary power 

 of mind in persons in other respects unhealthy, and whose 

 bodies have been enfeebled and almost destroyed by disease. It 

 will be adviseable in future to examine minutely the fibres which 

 compose the nervous parts of the brain in persons of different 

 kinds of constitution, to ascertain how far the demonstrable 

 constitution of nervous parts can be shown to agree with cir- 

 cumstances of constitutional character. Whatever discoveries 

 I should be fortunate enough to make in these investigations, I 

 shall communicate in the Philosophical Magazine ; and shall 

 proceed in some future Number to point out some other diffi- 

 culties we experience in judging of the activity of particular parts 

 of the head. 



Yours, &c. 



Clapton, July 4, 1815. ThOMAS FoRSTER. 



IV. Correction of some Errors in Mr. Singer's Paper on the 

 Mechanical Applications of the Electric Column. In a 

 Letter Jro7n the Author. 



To Mr. Tilloch. 



Dear Sir, — In the paper on the mechanical applications of 

 the electric column which you have lately published for me, there 

 is another error besides that you have noticed in your last erra- 

 tum. • The reference to the engraving is not only defective in 

 descril)ing it as Plate VII instead of Plate VIII., but by some 

 mistake of the engraver the reference figiues are misplaced. 

 The electric chime, wliich is referred to as fig. 1, has been num- 

 bered 3, andZamboni's vibrating needle, which I have described 

 as fig. 3, is numbered in the plate fig. I. 



I am sorry to ol)serve by a note in your last Number that my 

 mention of the electrical clock contrived by Mr. Ronalds has 

 called forth an invective against me from that gentleman, whose 

 ingenuity I have always been not only ready, but anxious, to no- 

 tice ; as the pages of your Journal, and my " Elements of 

 Electricity," suHiciently testify. 



I am not so fond of controversy as to trespass on your pages, 



or 



