Page:Popular Science Monthly Volume 80.djvu/404

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THE subject of food poisoning is one that is commanding a constantly increasing attention on the part of the general public. A brief resume therefore of the most important facts relating to ptomaines and ptomaine poisoning together with some deductions based thereon may be of interest to all who would be informed on matters relating to their physical welfare—certainly so to those who are practical conservators of the public health.

Ptomaines are chemical compounds of an alkaloidal nature formed in protein substances during the process of putrefaction. In order to a clear understanding of the subject, emphasis is to be laid on the fact that they are purely chemical bodies formed out of the medium in which they occur.

In this respect they are to be differentiated from the toxins, which are poisons of unknown composition, formed within the bacterial cell itself and in the case of certain organisms, given off to the medium in which they grow. They are also to be differentiated from another class of compounds known as leucomaines, which may in some instances be of like chemical composition, but which are formed only within the living body, usually as the result of tissue metamorphosis. From these, when not properly eliminated, we get the varied phases of auto-infection.

Putrefaction is the biochemical process by which all protein matter is reduced to the inorganic state from whence it came, thus completing the life cycle. This change is brought about by the action of microorganisms. A certain group of bacteria have the power to split up the complex protein molecule and thus form new and simpler compounds. As a result of their action we have formed first albumoses and peptones and from these we have formed the amino acids which are the great foundation stones of the proteins. These are still capable of sustaining bacterial life and the splitting-up process continues. As a result we may get a large number of products, solid (crystalline), liquid and gaseous—and among them may be some of the basic compounds which we call ptomaines.

So far about sixty ptomaines have been isolated and studied and of these about one half are more or less poisonous. It is to be borne in mind that the so-called ptomaines are not a distinct class of chemical compounds, but differ widely both in chemical composition and physical characteristics. Indeed it may be said that they have only this in common, that they are basic and contain nitrogen. Some of them are comparatively simple and well-known organic compounds like the simple