220 MICROSCOPICAL MEMORANDA. 



H assail on Showers of Pollen. The American Journal of Science and 

 Arts for January, 1842, (p. 195), contains some interesting remarks re- 

 lative to two showers of pollen, one of which fell at Troy, New York, 

 the other in the harbour of Picton, a portion alighting upon a vessel in 

 the harbour on a serene night in June, and having to be collected and 

 thrown over by the bucket-full in the morning. A small quantity of 

 each of these powders was preserved and sent to Prof. J. W. Bailey, to 

 submit to microscopic examination. This gentleman ascertained, that 

 the powder which fell at Picton was wholly composed of the pollen of a 

 species of pine, and that from Troy was made up of pollen from various 

 trees ; but Prof. Bailey was not able to state positively what plants fur- 

 nished it. Figures of the three forms of pollen granules met with in 

 the powder from Troy, accompany Prof. Bailey's letter. From an exa- 

 mination of these, I find that two of them are to be referred to some 

 Endogenous plant, one of them most probably to a species of grass, the 

 other perhaps to the genus Nymph&a, and that the third form is un- 

 doubtedly the pollen of an Exogen, not unlikely to be the Cory Ins. 

 Prof. Bailey thinks, that no part of the powder can be sporules of Lyco- 

 podium ; because, he remarks, our species of that genus do not flower 

 until July or August, whereas the powder in question fell in May. I 

 arrive at the same conclusion, but for a different reason ; the sporules of 

 Lycopodium do not present at all the structure of any one of the three 

 figures. Ann. Nat. Hist. June, 1842,;?. 353. 



Phillips on the Microscopic Structure of Coal. A paper was read 

 before the Geological Section of the British Association, in which Mr. 

 Phillips observed, that there was no difference of opinion as to the vege- 

 table origin of coal, but only as regarded the circumstances under which 

 those vegetable masses were accumulated. In order to determine this, 

 several modes of investigation might be followed, one of which was, to 

 examine the coal itself, in order to ascertain the nature of the plants of 

 which it is composed. In the microscopic examination of polished 

 slices of coal, by means of transmitted light, some results had been ob- 

 tained by Mr. Hutton of Newcastle ; these observations had not been 

 published, but he believed Mr. Hutton had detected a cellular structure 

 in the substance of the Northumberland coal, which at first sight might 

 be imagined vegetable cells. These cells had been supposed to contain 

 much, if not all the gas of the coal ; and in this respect the Northum- 

 berland coal differed from the anthracitic, in which the cells were empty. 

 It had been his intention to employ some of the ingenious processes 

 recommended by Mr. Reeve, who had discovered the means of making 

 fossil vegetable tissue apparent to the senses by a process of combus- 

 tion ; but having lately observed something remarkable in the combus- 

 tion of Staffordshire coal, he was induced to examine it microscopically, 

 without waiting to adopt any more refined process. He observed that 

 the ashes of wood and peat differed in appearance and structure ; and 

 this Staffordshire coal, which did not cake, but burned to a white ash, 

 resembled in its combustion the laminated peat of the north of England, 

 or the compact black peat of Dartmoor. Upon examining these ashes, 

 he found abundant traces of vegetable structure, consisting of small por- 



