538 
FACTS AND OBSERVATIONS. 
sheep poisoned observed on the same farm that cows had 
eaten with impunity of the same beetroot pulp which had 
poisoned the sheep.^’— Review, May 1863. 
Skeleton of an Extinct Ox in the Fens. —Much 
interest has recently been excited in the minds of geologists 
and students of the earliest history of the world by the dis¬ 
covery, at Burwell, of a skeleton of the huge extinct ox {Bos 
primigenius), formerly an inhabitant of our fens, having a 
fractured skull, in which was a broken flint celt. At a recent 
meeting of the Cambridge Philosophical Society a paper 
upon the subject was read by Mr. James Carter. The height 
of the animal, it was stated, must have been from six to seven 
feet. The celt pressed in its forehead was undoubtedly, Mr. 
Carter considered, of human fabrication, and he thought it 
equally evident that the fracture had been produced by this 
celt. It penetrated the cavity of the skull for nearly three 
inches, and then broke off at a point that would have been 
on a level with the skin of the living animal; to all appear¬ 
ances it was broken in the act of inflicting the blow, and, as 
this mutilated implement was of no further use to the pri¬ 
meval hunter, it was not extracted from the skull. As 
regarded the antiquity of the remains, the author inclined to 
the opinion that they need not necessarily be referred to any 
very remote period, probably to none more remote than the 
Saxon period. The time up to which the early inhabitants 
of the fen district continued to use flint instruments was, he 
thought, more recent than commonly supposed, but the most 
careful records contained no account of any discovery to elu¬ 
cidate the question, or to add anything to the past history of 
the fens. 
Liebig on London Sewage. —Liebig calculates the 
solid and liquid voidings of London would yield 42 tons of 
ammonia, 10 of phosphoric acid, and 7-^ of potash daily; 
the ammonia equal to that contained in 247 tons of guano, 
the phosphoric acid equal to that contained in 83*3 tons 
of guano. If, therefore, to the daily sewage of London 100 
tons of superphosphate of lime, containing 20 per cent, of 
phosphoric acid, be added, the value of the daily voidings ^ 
of London is made equivalent to that of 247 tons of Peruvian 
guano. The yearly value of the sewage, after deducting the 
price of the superphosphate, would be that of 90*135 tons of 
guano at £13 125. QcL per ton, minus £l91j628, or £1,036,628. 
If to this be added the value of the surplus potash in the 
sewer water, it gives a total of £l,109j006 annually. The 
