1863.] On the Amy I Compounds derived from Petroleum, 131 



From inquiry amongst the Bedouins and European residents in Palestine, 

 it was ascertained that during the early summer the level of the sea falls 

 at least 6 feet below the level at which it stood on the day the levelling was 

 taken, which would make the depression 1298 feet; and we may conclude 

 that the maximum depression at no time exceeds 1300 feet. Lieut. 

 Symonds, K.E., in 1841, made the depression 1312*2 feet. 



The soundings in the Dead Sea by Lieut. Vignes of the French Navy, 

 gave a maximum depth of 1148 feet, making the depression of the bottom 

 of the Dead Sea 2446 feet below the level of the Mediterranean. The 

 soundings in the Mediterranean, midway between Malta and Candia, by 

 Captain Spratt, R.N., gave a depth of 13,020 feet, or a depression of the 

 bottom five times greater than that of the bottom of the Dead Sea. 



The levelHng was executed by two independent observers, and from a 

 comparison of the two sets of levelling, it is certain that the levels have 

 been obtained with absolute accuracy to within 3 or 4 inches. 



The estabHshment of a chain of levels across the country with bench 

 marks cut on so many points, cannot but prove of the utmost importance 

 for any future investigations, or for any more extended surveys in Palestine, 

 such as are contemplated by the Society which has been formed since this 

 survey was made, " for the accurate and systematic investigation of the 

 archaeology, the topography, the geology, and physical geography, &c. of 

 the Holy Land, for Biblical illustration." 



For the survey of Jerusalem itself, it was of the utmost importance, as 

 it enabled us to connect all the levels in and about the city with the level 

 of the Mediterranean, and to harmonize, so to speak, all the levels which 

 have been taken. 



II. " Note on the Amyl-Compounds derived from Petroleum.^^ 

 By C. ScHORLEMMER. Communicated by Professor Roscoe. 

 Received April 26, 1866. 



In a former communication I have shown that the hydride of heptyl 

 obtained from petroleum has a higher specific gravity than its isomers 

 ethyl-amyl, and hydride of heptyl from azelaic acid. The same is the 

 case with their derivatives, and some of these isomeric compounds also 

 show considerable differences in their boiling-points *. I could not com- 

 pare the different heptyl-compounds which I prepared with those of 

 heptyl-alcohol formed by fermentation, as the latter substance is veryUttle 

 known, and I therefore considered it interesting to compare the amyl- 

 compounds from fusel-oil with those obtained from petroleum. From the 

 latter substance I prepared a considerable quantity of pure hydride of 

 amyl, which boiled constantly at 33°-35° C. ; and I did not succeed in 

 lowering the boiHng-point any further. From this hydride other amyl- 

 compounds were obtained in exactly the same way as the heptyl-com- 

 ^ Proc. Roy. Soc, vol. xiv. p. 464. 



VOL. XV. N 



