Certain of these bases are very toxic, for instance trimethylene diamine, the collidines, and the parvolines. _b._ =Guanidines.=--Among the products of ordinary putrefaction there has been found so far only methylguanidine, C{2}H{7}N{3}. This is a highly toxic base of which 0.2 Gm. is fatal to a guinea-pig. _c._ =Oxamines.=--Under this designation the following bases are comprised: 1. Neurine bases; 2. oxygenized aromatic bases; 3. bases of unknown constitution. Amongst them we find neurine and choline, which are toxic, and betaine, which is innocuous. They are found particularly in putrid fish. _d._ =Amido Acids.=--These ptomaines, which are usually innocuous in small quantities, are particularly the products of the decomposition of albuminoid substances. Among them we find glycocoll, leucine, and tyrosine, as members of this group. _e._ =Carbopyridic and Carboquinoleic Acids.=--So far only one base is known belonging to this group, and that is morrhuic acid, which is found in the decomposed livers of codfish, and which is a powerful appetizer and stimulant in disassimilation. _f._ =Undetermined Ptomaines.=--Under this heading are classed certain undetermined bases, such as those found in normal urines, and in spoiled meats and bread. BASES OF GROUP II. _a._ =Ptomaines Isolated from Cultures of Pathogenic Bacteria.=--Bacterial cultures contain, besides the true toxins, a certain number of alkaloidal bases which sometimes possess considerable toxicity. In the cultures of streptococcus pyogenes there are found trimethylamine and xanthic bases; in those of staphylococcus pyogenes aureus are found xanthic bases and creatinine; while pyocyanine and pyoxanthine are found in the cultures of bacillus pyocyaneus, etc. _b._ =Ptomaines Isolated from Pathological Urines.=--Toxic ptomaine bases have been found in the urines of a large number of diseases.[8] It is quite probable that these bases are the results of a general pathological condition due to some bacterial disease, the toxic products of which are eliminated by the kidneys. [8] GRIFFITHS: _C. rend. de l'Académie des Sciences_, CXV, pp. 285 and 667. From the urines of epileptics Griffiths[9] isolated a colorless base crystallizing in prisms having the formula C{12}H{15}N{5}O{7}, and which was found to be exceedingly toxic; the same investigator isolated from the urines of eczematous subjects a ptomaine which he named _eczemine_,[10] and which is also highly toxic. [9] E. POUCHET: Contribution à l'étude des matières extractives de l'urine, _Thèse_, Paris, 1880; _Ibid._, _C. rend. de l'Académie des Sc._, XCVII, p. 1560; BOUCHARD: _C. rend. Soc. de Biolog._, Aug. 12, 1882. [10] GRIFFITHS: _C. rend. de l'Académie des Sciences_, CXVI, p. 1206.