1869.] Chemistry. 275 



ethyl etlier, it sinks to the bottom of the vessel. All attempts at 

 further purification failed ; the liquid boils at 75° under decomposi- 

 tion. Organic chlorides are converted into iodides by the action of 

 concentrated iodhydric acid. M. A. Lieben finds that this method 

 of conversion seems to be a general one, and subject to limitation 

 only in so far as some iodides at the moment of their formation are 

 converted into hydride. Ethyl chloride, at 130^ C, is almost com- 

 pletely converted into iodide, without evolution of gas or formation 

 of any bye-product. The same is the case with butyl and amyl 

 chloride. 



Lipowitz has recommended the use of hypochlorite of lime 

 (bleaching powder) as a means of detecting the adulteration of olive 

 oil, and also of sweet almond oil, with the oil of poj)py-seed. When 

 eight parts of either olive oil or oil of sweet almonds is rubbed 

 up and shaken with one part of bleaching powder, and left at rest, 

 it will be seen that even after some four or five hours a layer 

 of clean and limpid oil separates and floats at the top and surface of 

 the mixture, which layer is, if the oils operated upon are pure, at 

 least half the bulk of the original mixture ; if, however, poppy-seed 

 oil is mixed with either of the two oils just mentioned, and the same 

 experiment then repeated, the mixture takes the appearance of a 

 liniment, from which no oil separates. Sweet oil of almonds adul- 

 terated -with one-eighth part of poppy-seed oil behaves as if it were 

 almost pure poppy-seed oil. Biichner and Brande have found 

 Lipowitz's statement correct as regards sweet oil of almonds, but not 

 as regards oil of oHves ; but they add that the olive oil they 

 operated upon was already old. The action of Lipowitz's reagent 

 is explained by the fact of the rapid oxidation of all so-called drying 

 oils, which on drying yield solid products before entirely changing, 

 by continuously absorbing oxygen into water and carbonic acid. 

 Linseed oil, hemp-seed oil, poppy-seed oil, oil from walnuts, croton 

 oil, castor oil, are all drying oils. The drying of drying oils is, in 

 fact, a process of slow oxidation of these oils. 



Professor Parkes, F.K.S., of Netley, calls attention to the fact 

 that it has always been seen that the action or non-action of water 

 on lead could not be entirely accounted for by the usual statenients 

 on the subject ; and lately Dr. Frankland has made a curious 

 observation, which may throw light on the subject. He found that 

 water which acted on lead lost this power after passing through a 

 filter of animal charcoal. He discovered this to be owing to 

 a minute quantity of phosphate of lime passing into the water from 

 the charcoal. On comparing two natural waters, that of the river 

 Kent, which acts violently on lead, and that of the river Vyrnwy, 

 which, though very soft, has no action on lead, he found that the 

 latter water contained an appreciable amount of phosphate of lime 



