PROCEEDINGS 1841—1848. 
195 
Mr. Henry Briggs contributed a paper on " Lime and its uses 
in Agriculture," in which he gave a series of analyses of the Lime- 
stones obtained from the Chalk, the Magnesian .Limestone, and the 
Carboniferous Limestone, pointing out that the upper beds of the 
Magnesian Limestone contained only a minute trace of Magnesia, 
whilst Carbonate of Lime existed to the extent of 94 per cent. ; in the 
lower thick-bedded Magnesian Limestone the proportion of Carbonate 
of Lime amounted to 62 per cent., and that of Magnesia to 36. He 
advised the use of lime for districts in which the water (which he 
took as a fair guide) contained very little, especially mentioning the 
districts bordering on the Penine Chain. 
In 1845 Professor John Phillips, of York, contributed two papers, 
one of which was on " The Remains of Microscopic Animals in the 
Rocks of Yorkshire," and the other on " Observations on the Process 
of Petrifaction." In the latter he alluded to a subterranean forest 
which had recently been found in the neighbourhood of Ferrybridge, 
whilst cutting the Aire and Calder Canal. The soil was alluvial. 
The forest was composed mostly of hazel bushes, containing fine 
clusters of nuts, at a depth of about fourteen feet. In some instances 
the wood remained unchanged, whilst in others the external part was 
converted to stone, but in all instances the bark retained its vege- 
table character. On examining the nuts he found the external shells 
were entirely unaltered, but the kernels were converted into stone. 
He had examined a portion of the wood so converted into stone 
under a microscope, and it presented as beautiful and as perfect a 
specimen of hazel wood as could be seen. With respect to the nuts 
he believed that the change was owing to their having been permeated 
by water that had passed over a bed of limestone. The Professor 
next described an ancient boat which had been found embedded in 
the banks of the Calder near Stanley Ferry, and also the lower jaw 
of a red deer found a few years ago embedded in Hatfield Chase . 
The jaw bones and teeth of the latter were quite flexible : they had 
lost the whole of their hardening earth and retained the gelatine. 
The latter had become tanned by the peat, and thus the whole was 
actually converted into leather, and was as pliable and flexible as a 
piece of ordinarily prepared leather. In the former paper Professor 
