252 Discovery of the secret Destroyers 



By this operation we have the following derivative equa- 

 tions, 



B,= fB +A 



c,; = <B, + B, 



d; = cc, + c. 



&c. 

 which show the law of derivation. 



[To be continued.] 



LI. Discovery of the secret Dcstroijers of the Trees in St. James's 



Park. 



To the Editors of the Philosophical Magazine and Journal. 



''I "'HE alterations which are now taking place in the Parks, 

 -^ and particularly in St. James's Park, evidently excite a 

 good deal of public interest. Few persons, however, seem 

 aware that the greatest change which is about to be effected 

 in the appearance of these '■'■ Lungs of London" is one which 

 is contemplated by none with less pleasure than by those who 

 have the care of them. Few persons suspect, for instance, 

 that in a very short period St. James's Park will be clothed 

 in the dapper dress of a nursery plantation, and will have lost 

 those shady avenues and that antiquated appearance which 

 are all associated with the recollections of times gone past. 

 So rapidly, however, is it advancing to this state, that every 

 person who is in the habit of entering it must perceive that, 

 unless some remedy be quickly applied, a few months have 

 only to elapse when there will be scarcely any thing green 

 in it but the grass. Of the saplings which have been lately 

 planted I do not speak; but it is manifest that every thing 

 deserving the name of a tree, a few limes only excepted, is 

 rapidly disappearing. In spring we see the leaves sprout 

 forth from the venerable trunks in all the luxuriance of vege- 

 tation, when of a sudden they are blasted as if by lightning, 

 the bark falls from the stem, and long ere winter the finest 

 tree perhaps in the park is only fit for fire-wood. Whole rows 

 have thus disappeared and are still rapidly disappearing in 

 the Mall and Bird-Cage Walk; and as it is anticipated that 

 the public will esteem this open condition of the park to be 

 little conducive to its beauty, even if it should add to its salu- 

 brity, great pains have of course been taken to find out the 

 cause of the misch.ief. 



As it was clear that the trees died in consequence of being 

 completely stripped of their bark, rewartls were at first offered 

 for the discovery of the persons who so mischievously barked 

 them ; but in vain. It was observed, however, very ingeniously, 



that 



