310 A MANUAL OF BACTERIOLOGY 



addition of sodium carbonate, and is once more 

 agitated with half its volume of ether. The ethereal 

 solution (after standing) is separated, and the ether 

 allowed to evaporate spontaneously. The residue 

 (after drying over sulphuric acid) is finally examined 

 for ptomaines. 



The ptomaines or animal alkaloids are divided 

 into two groups the non-oxygenous and the 

 oxygenous ptomaines. 



(A.) The Non-oxygenous Ptomaines. 



Parvoline (C 9 H 13 N). This base was isolated by 

 Gautier and Etard, from mackerel and horse-flesh 

 after bacterial putrefaction. It is an oily yellow 

 base, with the odour of hawthorn. 



Collidine (C 8 H n N) or isophenylethylamine 



C 6 H 5 CH was discovered by Nencki in 



1876, among the products of the bacterial putrefac- 

 tion of gelatine and the pancreas of the ox. An 

 isomeride of this ptomaine was isolated by De 

 Coninck from the muscular tissues of the cuttle- 

 fish (Sepia) ; and it is probable that it has the con- 

 stitutional formula of dihydropyridine. Collidine 

 is a yellow fluid with an offensive odour ; and it 

 is soluble in water, alcohol, and ether. 



Coridine (C 10 H 15 N). This ptomaine was ex- 

 tracted by Guareschi and Mosso from the bacterial 

 putrefaction of fibrin. It is an oily fluid, having a 

 slight odour of pyridine and conicine. It forms a 



