390 Scientific Intelligence. []^ov. 



case also with the slate clay and the coal which alternate with 

 this sandstone. Indeed if the coal formation exists as a portion 

 of the old red sandstone, we can entertain no reasonable doubt 

 that the old red sandstone itself has been formed after the earth 

 was covered with wood ; so that the fancies (for I can give them 

 no other name) lately advanced respecting its being an original 

 deposit cannot be supported with any regard to the rules of cor- 

 rect reasoning. If it turn out to be true, as there is some reason 

 for beheving,"that the transition and some of the primitive rocks 

 alternate with the old red sandstone, \^e must conclude that 

 these rocks also have been formed after the earth had been 

 covered with wood. 



II. Remarkable Instance of Spontaneous Combustion. 



It is the custom with many of the merchants and manufactu- 

 rers of Glasgow to spend several of the summer months at sea- 

 bathing quarters, leaving the care of their town houses to a 

 single servant, or sometimes shutting them up altogether. A 

 gentleman, a neighbour of mine, removed with his family to 

 Largs in May last, carried with him all his servants, and shut up 

 his house. It was opened for the first time about the end of 

 August, The house stands on the side of a pretty steep decli- 

 vity, so that the kitchen, which is in the back part of the house, 

 though sunk considerably below the level of the street, is 

 entirely above ground. It is remarkably well lighted and venti- 

 lated. I was in it on the day that the house was opened 

 without perceiving any unusual appearance of dampness. In an 

 opening of the wall near the kitchen fire, originally intended, I 

 believe, for an oven, there was placed a wooden barrel, bound 

 with iron hoops, and filled with oatmeal. This meal had heated 

 of itself during the absence of the family, had at last caught 

 fire, and was totally consumed, together with the barrel which 

 contained it, nothing remaining but the iron hoops, and a few 

 pieces of charcoal. I presume that the meal had been somewhat 

 moist, and that it had heated precisely in the same way as hay does 

 when stacked moist. The great avidity which oatmeal has for 

 moisture, and the heat generated by its absorption of it, must 

 be familiar to every one who has been in the habit of seeing oat- 

 meal. Indeed Mr. Leslie found that its avidity for moisture was 

 so great that it could be substituted for sulphuric acid in his 

 well-known method of freezing water by confining it over sul- 

 phuric acid under the exhausted receiver of an air-pump. 



III. Urea. 



The well-known substance in urine to which the name of urea 

 was given by Fourcroy, seems to have been originally noticed by 

 Rouelle. Fourcroy, in deference chiefly to the opinion of Dr. 

 Pearson, gave the name oi.vric acid to that peculiar substance, 



