256 ODOKOGRAPHIA. 



280 c. c. each. The bisulphite solution contained 1000 grams dry 

 sodium bisulphite in two litres of water. 250 c. c. of this was 

 added to each portion of oil and the mixture well stirred. During 

 the stirring the vessels were kept cool with ice water. After 

 about ten minutes the mixture " set," forming a snow-white 

 magma. The remainder of the bisulphite was now gradually added, 

 stirring all the time. A further evolution of heat took place until 

 all the oil had been precipitated. After standing about an hour 

 the mass was wrapped in flannel and after draining on a large 

 funnel, was carefully pressed in a filter-press. When the mass 

 was pretty dry it was removed from the press, thinned out 

 thoroughly with ether, and again drained and pressed. The 

 bisulphite compound was now tolerably free from residual oil. To 

 remove the ether it was exposed to the air for several hours. At 

 this stage it has the appearance of wax. On long exposure it 

 decomposes, turning yellow on the surface. To liberate the 

 aldehyde the dry mass was mixed with crystallised sodic carbonate, 

 450 grams of the former to 350 grams of the latter, in a large 

 flask. Steam was then passed into the mixture, which soon 

 liquefied and yielded the aldehyde as a distillate. 



The steam-distilled aldehyde, after drying several days over 

 calcic chloride, is a colourless oil having a sp. gr. at 25^ C. of 

 0'8509. It commences to boil at 202° C. and the temperature 

 slowly rises to 207*"' C, after which, it rises more rapidly (being 

 decomposed by the heat) and a resinous mass remains in the flask. 

 The vapour density determination by the method of Victor Meyer 

 gave D = 5405 : calc. — 5"o4. This aldehyde appears to be 

 dextrogyre : a column 2 decimetres long produces a deviation of 

 about 7*^ for sodium light. 



Tiie aldehyde readily absorbs bromine, the solution becoming 

 warm. If the temperature rises too much, hydrobromic acid is 

 given off and decomposition takes place. To determine the 

 amount of bromine absorbed, it was found convenient to weigh 

 quickly about one gram, of aldehyde, dissolve it in 20 c. c. of 

 chloroform or carbon disulphide, and run in, from a burette, a 

 standardised solution of bromine in carbon disulphide, until a 

 slight permanent red coloration was obtained. The bromine 

 solution used contained 0'1163 gram, bromine per c. c. The 

 following results were obtained : — 



