VARIETIES. 119 



the phenomenon of the Will o'the Wisp by their own fire- 

 sides, it may be easily done by the following method : — Into a 

 tumbler or any other vessel filled with water, drop a few small 

 pieces of phosphuret of lime ; the water will be in part decom- 

 posed ; and the phosphorus combining with the hydrogen, will 

 form phosphuretted hydrogen gas ; bubbles of which will be 

 seen rising to the surface, where they will immediately inflame 

 upon coming in contact with the air, and exhibit a pale and 

 somewhat ghastly flame ; should an inverted jar of oxygen be 

 held over the water, the bubbles will in like manner inflame, 

 but with a light which is most dazzlingly brilliant. The in- 

 tensity of the light of the flame, therefore, it would appear, 

 depends upon the quantity of oxygen contained in the atmo- 

 sphere to which it is exposed ; and it would of course follow that 

 in bogs, and other damp places, where the air is impure and 

 its comparative quantity of oxygen but small, the flame would 

 be so faint as to be scarcely visible in day-light, though per- 

 fectly apparent at night. 



Phosphorus forming one of the component parts of all 

 animal and vegetable matter, it is obvious, that in the course 

 of the decomposition of such matter it must be set at liberty in 

 considerable quantities, when, combining with the hydrogen of 

 the water of the surrounding soil, it forms the gas, which, 

 making its way to the surface of the earth or water, as the 

 case may be, ignites immediately it comes in contact with the 

 atmospheric air, and thus forms in church-yards, morasses, and 

 other damp places, the phenomenon which has caused the 

 heart of many a stout yeoman to beat with superstitious awe. 



R. A. Ogilvie. 



11. Aleyrodes Phillyrees. — About the end of May I found 

 the different species of Pltillyrea, particularly the media and 

 latifolia, in gardens near Dublin, swarming with this pretty 

 species. They covered the under sides of the new leaves, from 

 four to a dozen sitting under each ; and the leaves of the former 

 year were equally loaded with their puparia, from which they 

 seemed to have just emerged. The lower surface of the young 

 leaves was whitened with their powder and strewed with eggs, 

 scattered irregularly, and not in patches : these are transparent 

 when laid, soon become wax - coloured, and in a few days 

 opaque, glossy, pearl - grey. They are much longer in the 



