Chesterton was vehemently opposed to suicide, he considered it an insult to all creation.
An Envoi added at the end of a poem is an ancient device, originally a few lines addressed to the poet's patron. Now it's usually a comic addition addressing oneself, as it is here.
en.wikipedia.org/wiki/Envoi
Germinal was a month in the calendar of the French Revolution, and in Germinal George Danton and his followers were executed. They were called the Indulgents because they advocated leniency. Tumbrils were carts used to convey the condemned to the guillotine. In this Envoi Chesterton tells himself that the tumbrils are already rolling, death is inevitable and there is really no need to commit suicide.
He says that your reason for living need only be slight, such as a new way to cook mushrooms, a book that you always meant to read or appreciation of the beauties of nature.
When John Steinbeck was dying he made a farewell tour of America in a camper van (RV) together with a poodle, which he recorded as, "Travels with Charley". He stocked his camper with all the books he had always meant to read. It was a sad day when he realised that these were books that he would never get around to reading.
en.wikipedia.org/wiki/Travels_...
Whatever you are, you are not insignificant. The odds against you being here at all are astronomical. One man produces more individual sperm in his lifetime than there are human beings on earth. You already won the sperm race: don't stop wriggling now. At least, pay attention to your surroundings. You can change them, you know. Let the hangman guess your weight or the executioner sharpen his chopper: they have to live even if you don't. And if you really must die then choose a good cause - but, better still, wait for a natural one.
Gallows picture:
lastchancewar.blogspot.co.uk/2...
The gallows in my garden, people say,
Is new and neat and adequately tall;
I tie the noose on in a knowing way
As one that knots his necktie for a ball;
But just as all the neighbours-on the wall-
Are drawing a long breath to shout "Hurray!"
The strangest whim has seized me. . . . After all
I think I will not hang myself to-day.
To-morrow is the time I get my pay-
My uncle's sword is hanging in the hall-
I see a little cloud all pink and grey-
Perhaps the rector's mother will not call-
I fancy that I heard from Mr. Gall
That mushrooms could be cooked another way-
I never read the works of Juvenal-
I think I will not hang myself to-day.
The world will have another washing-day;
The decadents decay; the pedants pall;
And H.G. Wells has found that children play,
And Bernard Shaw discovered that they squall,
Rationalists are growing rational-
And through thick woods one finds a stream astray
So secret that the very sky seems small-
I think I will not hang myself to-day.
ENVOI
Prince, I can hear the trumpet of Germinal,
The tumbrils toiling up the terrible way;
Even to-day your royal head may fall,
I think I will not hang myself to-day.