220 EXPERIMENT ON CANDLE LIGHT. 



Experiment with I wo inches. The fhadow into which the large candle threw 

 V. h J" and a its light, was evidently ruddy or brownilh, while the other 

 cmdle. fhadow illuminated by the fmall flame, feemed to have a 



blutfh tinge. The flames themfelves appeared to differ in their 

 afpect; in the Tame manner as their fhadows : now the lights 

 emitted being inverfely as the fquare of the diftances, will be 

 as 36 to 64, or as 9 to 16 ; and when both were extinguished, 

 it was found that three inches of the large candle had been 

 burned, and 5.8 inches of the fmaller : but of the larger 

 candle, fifty-four inches in length make one pound, and of the 

 fmaller 192 inches make the pound; and if we divide 54 

 inches by three, the quotient will be 1 8, which (hews, that 

 the whole pound of large candles would have required 

 eighteen times our period for its confumption : in like manner, 

 by dividing 192 by 5.8, we have a quotient of 33.1, or the 

 time of burning a pound of the fmall candles. And laftly, if 

 we multiply the quantity of light afforded by each candle, by 

 the time required to confume a pound of each, we fhallhave 

 the proportionate quantities of light afforded by equal expen- 

 ditures of the combuftible, that is to fay, 18 multiplied by 16, 

 produce 28S, or the light afforded by the larger candle, and 

 33.1 multiplied by 9, gives 297.9 for the fmaller: which is 

 one part in 29 in favour of the fmall candle. 



I confider this difference as a greater quantity than the 

 errors of experiment, though upon the whole, it feems to con- 

 firm Mr. Walker's doctrine. 



Reft 

 tailed 



SCIENTIFIC NEWS. 

 On the Nutriment to be obiained from Bones, 



efuks asde- J[N" the firfl volume of the octavo feries of this Journal, page 

 jed j rouft. I0Q ^ not j ce n ta k en of the experiments on this fubject, detail- 

 ed by profefifor Prouft of Madrid, in his inquiry into the 

 means of improving the fubfiftence of the foldier. He ilates 

 the quantity of jelly obtained from bones to be very variable, 

 according to the. nature of thofe employed, viz. from nine 

 pints to thirteen quarts, from five pounds of bones; thofe from 

 the rump and fpine yielding the moll and befl ; and thofe of 

 the legs and thighs the leaf! and molt unpalatable. i 



Sine 



