1 8 1 6. J UnUty of Pcriodi 



arc -similar by Euclid's demonstration, and 

 the an:;Ie B C F equals the angli,' I> D A ; 

 but, because A L and D H are parallel, 

 tlie aiij^le B D A equals the anjle ]) A L 

 (\x\\. 1), and DAL equals RCY. But 

 the ancles A L D, R Y C, are equal by 

 construction ; tlieretore D L ; L A : : R Y ; 

 C Y (iv. 6) ; and tlie rectangle D L, C Y, 

 equals the rectanj^ie A L, RY (xvi. 6) ; for 

 the same reason, the rectaufjle EL, B Y, 

 equals the rectangle A L, R Y ; therefore, 

 DL : EL :: B C : CY (xiv. 6), hence 

 U E : EL :: B C : C Y (xviii. ,=,), but D E 

 equals BC (xxxiv. 1), wherefore EL 

 equals C Y ; but E L and C Y are also pa- 

 rallel by construct. ; therefore Y L and E C 

 are parallel (xxxiii. 1) ; but the an!;le 

 C E L is ri^ht by construct, therefore 

 LY C h riglit(xxxiv. 1), and R Y C is right 

 by constrnot. ; therefore L Y and YR are 

 in the same straight Ime (xiv. 1) ; but LA 

 is parallel to C E by coustriict. therefore 

 QLE equals a ri;;ht angle, and also RLE 

 equals a right an«le, and Q L E, K L E, 

 equal two right angles; hence QL and 

 L R are in the same right line (xiv. J), but 

 QL, LA, are in the same right hue by 

 construct.; Iheitfore fi R, Q A, have a 

 common segment, Q L, which is inqiosni- 

 ble (xi. 1^; tliercfore QA passes through 

 R. Q. E. U. 



To the Editor of the Monthly Magazine. 



SIK, 



AIVIONG the causes wliicli Lave 

 tended to enlarge the boundaries 

 of science, and jiroinote the general dil- 

 fusiuii of kno\vl(!dge, tiie rapid circula- 

 tion of periodical publications claim a 

 distinguished rank. Every department 

 ioT tlie arts and sciences is indebted to 

 tbis source for the discovery and promul- 

 gation of valuable facts, and the detec- 

 tion and correction of numerous errors. 

 Tlie peculiar advantages the periodical 

 pfcss possesses over other vehicles of 

 intelligence, and which prove its claims 

 oh public patronage, arc — 



Ist. Tlie superior facility it affords a 

 Writer to connnuiiicatc his tlionghts to 

 the world ; an o|)i)ortunity is thus given 

 to individuals to make known their dis- 

 i-,o\eries, and to oiler tiicir observations, 

 which otherwise must inevitably have 

 remained latent. It is not the reailcr 

 ouly who is thus benefitted, but the 

 powers of the writer arc called forth ; 

 auil, to correct bis idias, and to embel- 

 lish his communication, he is induced to 

 *efer to books, whicli might have been 

 neglected, or, if ojicncd, rc.'id in a cursory 

 manner, wiiltoui reflection : he now shi- 

 dies their contents, and, exaniining the 

 arguments of the author with attcniion, 

 /eudcrs the ideas in some degree his 



cal Publications, 421 



own. A spirit of investigalion is ex- 

 cited, and a stimulus is given to intel- 

 lectual exertion, in ordcj- to appear be- 

 fore the public with credit. 



2d. Tlic more extensive circulation 

 that a person jnay obtain for his senti- 

 lacnt.s, by inserting tiiem in a periodical 

 Work, than he could easily obtain by 

 any other medium, has been justly no- 

 ticed by Dr. Johnson, in a passa"-e 

 yijii liavc judiciously selected for your 

 motlo. A third insianc* isin its allo^ving 

 a correspondent to express liimscif with 

 energetic brevity : he is not tempted to 

 spin out his arguments, and (iilnte iiis 

 ideas wilh a tedious ciienmlocution, jii 

 order " to make a book;" — a fault fre- 

 quently, and with too much justice, 

 complained ofia moncgraphic publica- 

 tions. 



The validity of tliese remarks is now 

 suftiriently aoKnowIedgcd, and the in- 

 creased number of periodical jcurnals is 

 commensurate with tiie improvement of 

 the times, and proves that their utility is 

 duly aiii)rcciiitcd and enconraged by an 

 enlighten<'d and discernin.r; public. The 

 motion of literature is constantly pro- 

 gressive; and many of tlie valuable addi- 

 tions, daily aiigmenting its stores, arc 

 brougiit into ligiit by the various works 

 of this nature. Who will deny that the 

 present arivaneed state of chcniistiy lias 

 hreli greatly owing to this source. In 

 medicine, the ccunplete renovation that 

 has taken place may be greatly attri- 

 buted to the same cause, l{y this 

 powerful literary engine, the vague theo- 

 ries and absurd liypoliieses of the an- 

 cients have been overturned, and tho 

 science of medicine, enriched by an in- 

 valuable mass of practical information, 

 has been constructed on rational and 

 consistent principles. Alfhougli it docs 

 not seem to have entered into tjjc cal- 

 culations of statistical writers, I think 

 that to the advancement of medicine as 

 a science, ami the greater sujcriority of 

 the modern 'Escula|)ii, together wit!) the 

 n)orc general practice of vacciiiation, 

 maybe justly assigned Iho considerable 

 increase in the j)opulation of tliis king- 

 dom, during a period when a v,ar, unpa- 

 ralleled ill sanguinary de.slructi(m of hu- 

 man life, mad.; incessant demands on its 

 most ellicient inhabitants. 



It has been urged that periodical 

 works too often contain the undigested 

 observations of iuc> perienced writers: 

 in a great variely of corre.spon.lent.s, 

 there must inevitably and necessarily be 

 dilfcrent gradations of merit ; but of its 

 injustice, as a gciiuu! muxi/u, the pages 



of 



