74 



HARDWICKE'S SCIENCE-GOSSIP. 



fell out of the fire on to its back, which caused it 

 to rush about the room, when the cinders were 

 deposited iu different places, which set fire to the 

 carpet. 



That mischievous animal the monkey has lent 

 its aid to the devouring element. Fires have 

 occurred through its agency, in a similar manner to 

 cats and dogs, also through its playing with fire in 

 various ways. In one instance a monkey upset a char- 

 coal brazier, and set a room on fire. Many— yes, very 

 many— fires have occurred through our domestics 

 hunting bugs and other small fry by the light of a 

 candle or lamp. In their anxiety, especially, to 

 hunt fleas, they forget they may and have produced 

 an enemy more to be dreaded. Many fires also 

 occur through persons fumigating apartments to 

 get rid of bugs and various kind of vermin. 



A few instances have occurred through the con- 

 centration of the sun's rays upon glass fish-globes. 

 On the 19th October, 1845, at two p.m., Mr. Phil- 

 brook's residence, Mill-street, Worcester, was set 

 on fire through the concentration of the sun's rays 

 upon a water-croft standing upon a table. Coloured 

 bottles in chemists' shops, cracks, and bull's-eyes 

 in glass have been known to focus sufficient heat 

 from the sun to set buildings on fire. 



Fires have occurred through the spontaneous 

 ignition of pigeon's dung under the slates and tiles 

 of houses. Professor Buckland traced two fires to 

 this cause.— See Builder, 28th September, 1844. 



Birds' nests under the eaves and wooden crevices 

 of houses, have been frequently set on fire through 

 sparks from a neighbouring chimney, and have con- 

 tained sufficient inflammable matter to set fire to 

 the buildings. 



Although I have given dogs the credit of pro- 

 ducing work for the flremen, still it would not be 

 fair if I were to omit to mention that they have 

 frequently discovered and given timely notice of 

 fires ; and many an anecdote can be told of the very 

 great interest dogs take in and at fires. 



Alfred Tozer. 



Chief Fire-station, Manchester. 



FOSSIL TEETH FROM THE NORTHUM- 

 BRIAN COAL-MEASURES. 



TOURING the last few months I have been 

 -^-^ examining microscopically all the teeth that 

 are known and named as belonging to tlie upper or 

 true coal-measures, and while pursuing these inves- 

 tigations, I alighted upon two teetli that were 

 certainly quite new to me, and I am inclined to think 

 they have never been discovered in any other locality, 

 as I cannot find mention of similar or anything like 

 similar teeth in Owen's " Odontography," Agassiz's 

 ^' Poissons fossiles," or any other paloeontological 

 work to which I have access. One tooth resembles 



somewhat in shape and structure a tooth of the 

 Selachian Ctenoptychiiis, though there are striking 

 diff'erences to be observed ; the other has no ally that 

 I can discover. 



The first was sent to me as a specimen of 

 Ctenoptychius by Mr. Salt, of Newsham, but a mi- 

 croscopical examination at once made it evident 

 that it could not be a tooth of that fish, though 

 probably belonging to the same family. It is very 

 small, being rather more than half an inch in length, 

 and one-fifth of an inch in height ; the superior 

 surface is convex and the inferior is concave; the 

 edges are narrow and rounded, from the convexity 

 being greater than the concavity. The superior 

 surface is denticulated, but the denticles are not 

 approximately uniform, as in Ctenoptychius (fig. 57), 



Fig. 56. Vertical Section of 

 New Tooth, nat. size. 



Fig. 57. Typical Tooth of 

 Ctenoptychius, nat. size. 



but decrease rapidly to mere points (fig. 56). The 

 four large denticles are rounded, and have on their 

 free surfaces from two to three sharp shining points, 

 the largest of these points being only -^ in. in height. 

 There is also a marked difference between the two 

 teeth in the form of the base, as will be easily seen 

 on comparing the above two engravings. 



The minute structure also differs very much, so 

 much, in fact, that it alone would cause the two 

 teeth to be allotted to different genera. 



In Ctenoptychius, the medullary canals are large 

 throughout the whole body of the tooth, they do not 

 become smaller as they approach the denticular 

 surface, they branch and anastomose very freely, 

 the branches being quite as large as the original 

 canal; thus it is impossibletosay whether the canals, 

 as a rule, run parallel with the axis of the tooth 

 (fig. 61). From all the canals spring numerous and 

 very large calcigerous tubes, some of the largest 

 measuring as much as ToVir of an inch in diameter, 

 the average being about TciroOf ^^^ 'mc\\. Thetubules 

 which arise from the canals in the body of the tooth 

 are very short, branch once or twice, the branches 

 anastomosing with their neighbours, and they ge- 

 nerally run at right angles to the canal from which 

 they spring; but those that proceed from the canals 

 near the denticles run parallel with the axis of the 

 tooth, tend to a fasciculate arrangement, do not 

 branch nor anastomose much, and retain the same 

 diameter throughout their course until they are 

 close to the periphery, when they become a little 

 finer, but are still comparatively coarse tubes (fig. 63). 

 The tubules can be easily observed under a power 

 of 20 diameters. There is not a vestige of ganoine 

 or fish-enamel in any of the sections in my posses- 

 sion, or in the sections that I have examined belong- 

 ing to other collectors. 



