150 ON THE FORMATION OF COAL \ 



the reason of the predominance of the spores and 

 spore-cases in it ? 



A ready answer to this question is afforded by 

 the study of a living full-grown club-moss. Shake it 

 upon a piece of paper, and it emits a cloud of fine 

 dust, which falls over the paper, and is the well- 

 known Lycopodium powder. Now this powder 

 used to be, and I believe still is, employed for two 

 objects which seem, at first sight, to have no par- 

 ticular connection with one another. It is, or was, 

 employed in making lightning, and in making 

 pills. The coats of the spores contain so much 

 resinous matter, that a pinch of Lycopodium pow- 

 der, thrown through the flame of a candle, burns 

 with an instantaneous flash, which has long done 

 duty for lightning on the stage. And the same 

 character makes it a capital coating for pills ; for 

 the resinous powder prevents the drug from being 

 wetted by the saliva, and thus bars the nauseous 

 flavour from the sensitive papilla of the tongue. 



But this resinous matter, which lies in the walls 

 of the spores and sporangia, is a substance not 

 easily altered by air and water, and hence tends 

 to preserve these bodies, just as the bituminized 

 cerecloth preserves an Egyptian mummy ; while, 

 on the other hand, the merely woody stem and 

 leaves tend to rot, as fast as the wood of the 

 mummy's coffin has rotted. Thus the mixed heap 

 of spores, leaves, and stems in the coal-forest would 

 be persistently searched by the long-continued 



