I'lTi PHILOSOPHICAL TRANSACTIONS. [aNNO 175/. 



Most part of the impressions of ferns, grasses, &c. are easily recognizable, 

 they so minutely tally to the plants they represent. Others indeed, though they 

 do not exactly answer any known species, yet have characters so distinctly ex- 

 pressed, that they are easily arranged under their respective genera. PI, 4, fig. 4, 

 5, 6, 7, 8, 9, 10 exhibits 7 of these impressions, out of many in his posses- 

 sion. Fig. 4 is from Mr. Mytton's collieries at Drilt, near Oswestry, in Shrop- 

 shire; as are also those figured N°. 5, 7, and 10: they are found sometimes 2 

 feet in length, and are generally covered with a thin crust of coal. N° 5 

 seems of the red tribe : the knobs placed in rows, which are like the vesicles 

 on the quercus. N° 6, from a coal-pit in Yorkshire ; seems to be owing to 

 something of the fir kind. N° 7 seems to be of the same kind as N° 5. The 

 extraordinary impression is from Mostyn-colliery in Flintshire. It is a little ob- 

 scured ; but, when attentively viewed, exhibits a reticular impression, the 

 meshes, which are rhomboidal hollows, and the sides of the rhombs, or the net- 

 work are raised, or in relief. N'' 9 is from Newcastle. 



These impressions are not only met with in small pieces ; but large evident 

 branches, some feet in length, have been found. He had, in the collieries of 

 Derbyshire, frequently traced branches with, seemingly, long narrow leaves pro- 

 ceeding from them, and parts of other vegetables, above a foot in length : but 

 the hardness of the substance they are immersed in renders it impossible to get 

 them out without breaking them to pieces : And these impressions, he thinks, 

 are to be ascribed to the Mosaic or universal deluge. 



XXIX. A Catalogue of the Fifty Plants from Cfielsea Garden^ presented to 

 the Royal Society by the Company of Apothecaries, for the Year 1756, pur- 

 suant to the Direction of Sir Hans Shane, Baronet, p. 236. 



This is the 35th presentation of this kind, completing a collection, to the 

 number of 1750 different plants. 



XXX. Remarks on the Opinion of Henry Eeles, Esq. concerning the Ascent 

 of Vapour, published in the Philosoph. Transact. Vol. xlix, p. 124. By 

 Erasmus Darwin,* M. D. Dated, Litchfield, MarchlS, 1757- p. 240. 

 The probability, supporting the hypothesis of Mr. Eeles, rests on this : ' That 



•Dr. Darwin, f. n. s. was born at Elston, near Newark in Nottinghanashire, December 12, 

 1731} and he died near Derby, April 18, 1802, consequently in the 7lst year of his age. His 

 &ther was a gentleman who possessed a good landed estate, and had a taste for literature and science. 

 And it would appear that the son's talents were first called into action by a correspondence with his 

 father. After his early education at Chesterfield school, he was entered at St. John's college Cambridge, 

 where he took the degree of M. B. in 1/55, defending in his thesis an opinion that the motion of the 



