464 Dr. Anderson on tlie Products of the 



in my former preparations. I subjected the whole of the oils 

 boiling above 212 to a systematic course of fractionation, each 

 fraction being distilled alone, and the product collected in a fresh 

 series of bottles, and the receivers changed at every ten degrees. 

 In the earlier rectifications each fraction spread itself over a 

 very large number of degrees, and showed little tendency towards 

 concentration to fixed points. The distillations were repeated 

 no less than fourteen times, but even after all this the indications 

 of boiling-points were extremely indistinct. Sometimes in one 

 distillation certain fractions appeared larger than others, but 

 their pre-eminence disappeared again in succeeding rectifications. 

 Still a certain improvement was manifest, some of the fractions 

 being confined more nearly to the range of degrees within which 

 they had boiled at the previous rectification. It was obvious, 

 from the whole phsenomena of the distillation, that the separation 

 of the difierent bases was going on, although with extreme 

 slowness ; and at this point I endeavoured, by the examination 

 of the platinum salts obtained at different temperatures, to 

 determine the constitution of the bases which these fractions 

 contained ; and as I knew from previous experiment that the 

 quantity boiling between 270° and 280° consisted of picoline, I 

 had from this fact indications of the temperatures at which bases 

 were likely to be found, and I have thus been enabled to deter- 

 mine the existence of two substances belonging to the same 

 homologous series with that substance. 



Pyridine. ^)W ^([.1 gnutiei 



The first of these bases, to which I give the name of pyridine, 

 occurs in the fraction boiling about 240°. This fraction has an 

 odour precisely similar to that of picoline, but more powerful 

 and pungent. It is perfectly transparent and colourless, and 

 does not become coloured by exposure to the air. It dissolves in 

 water in all proportions, and is also readily soluble both in the 

 fixed and volatile oils. It dissolves in the concentrated acids, 

 with the evolution of much heat, and the formation of highly 

 soluble salts. When bichloride of platinum is added to a solution 

 of its hydrochlorate, a double salt is slowly deposited in flattened 

 prisms, which are tolerably soluble in boiling water, less so in 

 alcohol, and entirely insoluble in ether. \\Tien these crystals 

 are boiled for a considerable time in water, they appear to 

 undergo decomposition, with the formation of a platinum salt, 

 crystallizing in golden scales. Two analyses of this salt were 

 made, one upon the substance simply precipitated from the 

 hydrochlorate ; the other was the same salt redissolved in hot 

 water, so as to leave a considerable proportion undissolved. In the 

 last analysis the salt was mixed with the chromate of lead when 



