37 



As the fat in this soil was found to be only 0.005 per cent, it does 

 not seem likely that tho pyridin forniod was duo to the formation of 

 the pyridin ring hy condensation, but rather that it exists already in 

 some form in the soil. 



Having in mind the light which has been thrown on the constitution 

 of complex pyridin compounds b^- oxidation processes, oxidation of 

 the soil by neutral and alkaline permanganate has been tried, and, while 

 no very definite results have been obtained, enough has been accom- 

 plished to warrant contiiming the work along this line. The action 

 of alkaline permanganate on these soils is very energetic, and large 

 containers are necessary to operate on quite small quantities of soil 

 without loss. 



The operation as carried on, without detailing unimportant varia- 

 tions, has been as follows: Permanganate, in small quantities at a 

 time, was added to the soil suspended in water or alkaline solution, 

 gentle heat being applied. When the addition of permanganate pro- 

 duced no further action, the manganese dioxid was filtered off, the 

 filtrate neutralized with nitric acid, filtered, and the filtrate treated in 

 various ways to recover oxidation products. This solution gives pre- 

 cipitates with lead, mercury, and silver salts, with cupric acetate in 

 the cold and a further precipitate on heating. When the perman- 

 ganate had been strongly alkaline there was obtained b}'^ decomposi- 

 tion of these precipitates with h^^drogen sulphid a residue mostly 

 crystalline, consisting for the most part of oxalic acid. By fractional 

 crystallization and treatment with different solvents there has been 

 obtained from this residue small quantities of a crystalline body giv- 

 ing pyridin on ignition with lime and the red color with ferrous 

 sulphate characteristic of several of the pyridin carboxjdic acids. 

 The production of a relatively large amount of oxalic acid by the oxi- 

 dation of the carbonaceous matter in the soil by the action of the per- 

 manganate is a serious obstacle in working along this line. 



When the oxidation is carried on with neutral permanganate, or 

 when the process in alkaline solution is not carried to completion, there 

 was obtained by the same procedure a dark red or brown, apparently 

 amorphous bod}^ which gave p3a-idin on ignition with lime. This, 

 apparently, is the body from which on further oxidation the pyridin 

 carboxylic acid is formed. 



At this stage this line of the w^ork stands at present. 



FUTURE WORK. 



Throughout the foregoing report enough worK has been outlined 

 for some time to come. The fodder analyses and research work will 

 be carried on along the lines indicated. 



Miscellaneous work will probably continue to come in, but the only 

 thing of this nature in view at present is the determination of the value 



