Atmospheric Effects of the Explosion of Gunpowder, 223 



beam, sycamore, tea, buckthorn, walnut, hazel, and many- 

 others ; as the leaves of all these contain much tannin, which 

 not only renders them imperishable, but, by contaminating 

 the water, prevents the decomposition of the other leaves 

 under maceration with them. 



I have found the following proper and easy Subjects : — 

 Leaves of the white poplar, black poplar, Lombardy poplar, 

 apricot, apple, orange, lemon, box, ivy, holly, many of the 

 exotic passion flowers; Magnok'tf glauca, acuminata, and 

 others ; lime tree, tulip tree. Calyxes of Moluccella lae\is, 

 which are, when prepared, very beautiful ; also the calyxes 

 and seed-vessels of Nicandra physaloides, of the winter cherry 

 (Physalis Alkekengi), of henbane (iiZyoscyamus niger); of all 

 the campanulas, particularly Campanula Medium (Canterbury 

 bell), C. rotundifolia (the harebell), and C. Trachelium ; the 

 larger mallows, the tree mallow (Lavatera arborea), hore- 

 hound (ikfarrubium album) ; Zfryngium Anderson/, alpmum, 

 campestre, and maritimum ; Medicago falcata and arborea ; 

 iStachys sylvatica, several of the nettles, Galeopsis Z,adanum, 

 Z)ictamnus albus, Phlomis fruticosa, Datura Stramonium, 

 A'troptf, the scutellarias, and the capsules of all the species of 

 poppy. To these may be added the stalks of cabbage, radish, 

 flax, hemp, and stinging nettles ; the tuber of the turnip ; 

 the involucres of Astrantia major and austriaca, and of the 

 Hydrangea Hortensia. 



Should not the above be sufficiently explicit, I shall be very 

 happy to remove any difficulties, either publicly or privately ; 

 and be gratified to show to any correspondent or reader my 

 collection of prepared specimens, which are numerous. 



It is right to observe, that I have seen many other leaves, 

 &c, of some of the thistles and of resinous plants, well 

 dissected : but with these I have not succeeded ; nor have I 

 by the process of boiling them in dilute acid, though I have 

 understood that, by this process, they may be done in a few 

 minutes. The proper acid, the strength of it, and the 

 manipulation required, I shall be glad to learn from any 

 correspondent. 



55. Great Prescott Street, Feb. 1835. 



Art. VI. A Notice of a Proposition that the Explosion of large 

 Quantities of Gunpowder, in Battles, effects extensive Changes in 

 the Condition of the Atmosphere. By Thomas Lee, Esq. 



The Rev. Mr. Clarke's communication, M On certain recent 

 Meteoric Phenomena," &c, in VIII. 1 — 28., brought to my 



