Dr. L. Moysey — On the Splitfing of Nodules. 221 



most part symmetrical, with smooth surfaces ranging in size from 

 a small orange to a large dinner plate, and in shape oval, round, or 

 flattened. Almost every nodule which was found naturally cracked 

 contained some organism or another in a good or bad state of 

 preservation ; it is therefore justiflable to assume that those nodules 

 which are still intact also contain organisms. Many of these stones 

 have been broken by mere brute force, always with the disappointing 

 result of obtaining a clean fracture without any sign of fossil ; or 

 perhaps the surface showed that a fossil was there, but that it was 

 completely ruined by being broken across in a plane a little above or 

 a little below its actual position in the nodule. Heating them to red 

 heat and plunging them in water was then tried ; but this apparently 

 was a too violent method, as the stone when it did break did so into 

 small fragments quite independent of the position of the fossil. The 

 method also is not unaccompanied with danger, as the stones are apt 

 to explode with great force, either in the fire or when plunged into 

 water. 



During this AVinter, however, several nodules, most of which had 

 been subjected to severe hammering to no purpose, were brought home 

 and frozen, with, as it seems to me, fairly good results. 



JSTothing of novelty, however, can be claimed for this method, as 

 it is probable that many geologists have made use of a freezing mixture 

 in this connection ; though there is scanty, if any, literature on the 

 subject, the late Professor Constantin Baron von Ettingshausen of Graz 

 in Austria practised it successfully on Tertiary shales containing fossil 

 plant-remains. 



The method now adopted was to keep the nodules soaking in 

 water, then to place them^ in a tin cannister, and surround the tin 

 with an ice and salt mixture in a pail. After leaving them in the 

 cold atmosphere thus generated for forty-eight hours, it was found 

 that most of them showed a crack running right round them. On 

 thawing, some were found to be cracked right through, and a light 

 tap with a hammer split them and revealed, in many instances, a very 

 perfect fossil. Others, however, though appearing to be cracked, 

 simply shelled off an outer husk of disintegrated stone, leaving a hard 

 solid core as refractory as ever, which, on again freezing and thawing, 

 sometimes split and sometimes cast off another shell. 



From these failures it was thought that perhaps the water did not 

 penetrate into the heart of the nodules in every instance, so several 

 nodules were heated gently to drive off the imprisoned air by 

 expansion, and were then plunged, while hot, into water. After this 

 treatment, in many instances, otherwise refractory nodules were 

 successfully split. 



A curious secondary result of these experiments has been the 

 discovery of a greater proportion of rare fossils in the nodules thus 

 artificially split than in those found naturally broken in the clay-pit. 

 Out of some ninety nodules cracked by freezing, there have been 

 found three specimens of Belinurus, one PalcBoxyris, two specimens 

 of a new shrimp-like animal, and one possibly new animal which may 

 turn out to be a complete but diminutive example akin to the 

 Artlirophiira armata of Jordan from Saarbrucken. 



