366 



DR THOMAS ANDERSON ON CERTAIN PRODUCTS OF DECOMPOSITION 



I was unable to obtain enough of oleic acid, I made use, in preparing it on the 

 large scale, of pure almond oil, which, according to Schijbler and Gasserovv, is 

 entirely free of margarine. The oil which I employed was expressed specially for 

 these experiments, at a temperature slightly above 32° ; and in order to satisfy 

 myself of the absence of margaric acid in the products of its ordinary decomposi- 

 tion, a quantity was distilled alone, and the product rectified. The latter por- 

 tions being collected apart did not deposit margaric acid ; and this I have also 

 found to be the case with the ordinary almond oil of commerce, in the expression 

 of which a moderate degree of heat is employed. 



In distilling the oil and sulphur on the large scale, it became impossible to 

 perform the process by the simple admixtm'e of the substances, the frothing being 

 so great as inevitably to expel the materials from the retort. After a trial of 

 various methods, I found it most convenient to employ the apparatus, of which 

 this is a sketch. The oil was introduced into a large glass balloon, to the mouth 



of which two tubes were adapted, one descending to near the middle, and fur- 

 nished with a cork at the upper end, the other which constituted the neck of the 

 distilling apparatus passed into a tubulated receiver, kept cold by immersion in 

 water or ice. To the tubulature, a doubly bent tube was affixed, which descended 

 into a vessel of alcohol, for the purpose of retaining any of the more volatile por- 

 tions which might be carried over by the rapid cuiTent of sulphuretted hydrogen. 

 The heat must be applied by means of an open charcoal fire, and the furnace 

 should be so constructed, that the fire may be rapidly withdrawn in the event of 

 the action becoming too violent. It is very desirable too, that the baUoon should 

 go down into the furnace, so that it may be entirely surrounded by hot air. The 

 oU is introduced into the balloon, of which it must not occupy more than a fifth, 

 or a fourth at most, along with a few small pieces of sulphur, and heat is gradu- 

 ally applied. So soon as effervescence commences, the cork of the smaU tube is 

 withdrawn, and a small piece of sulphur is introduced ; and this is continued 

 gradually, so as to keep up an uniform action. A dark reddish-brown oU passes 



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