In the long years of imprisonment which followed—the doom of the stake being averted only by powerful intercession with the Pope—Bacon had leisure to meditate on the value of all he had done to enlarge the understanding and extend the knowledge of his species. ‘The prelates and friars,’ he wrote in a letter which still remains, ‘have kept me starving in close prison, nor will they suffer anyone to come to me, fearing lest my writings should come to any other than the Pope and themselves.’ He reflected that of all living men he stood well nigh alone in the consciousness that in the greatest of his inventions he had produced a discovery of incalculable value, but one for which on every account the time was not ripe. ‘I will not die,’ he said, ‘without leaving to the world the evidence that the secret was known to me whose marvellous power future ages shall acknowledge. But not yet shall it be revealed. Generations must pass away and the minds of men become better able to endure the light of science, before they can profit by my discovery. Let him who already possesses knowledge, guess the truth these words convey.’ And in place of the directions by which Hubert de Dreux had been guided, he altered the sentence as follows:— ‘Sed tamen salis petræ, LURU MONE CAP UBRE et sulphuris.’ The learned have found that these mystical words conceal the anagram of _Carbonum pulvere_, the third ingredient in the composition of Gunpowder. “A GOOD PLAIN COOK.” ‘WANTED, a good plain Cook,’ is hungrily echoed from the columns of the _Times_, by half the husbands and bachelors of Great Britain. According to the true meaning of the words ‘A good plain Cook’—to judge from the unskilful manner in which domestic cookery is carried on throughout the length and breadth of the land—is a very great rarity. But the conventional and the true meaning of the expression widely differ. ‘What is commonly self-called a plain cook,’ says a writer in the _Examiner_, ‘is a cook who spoils food for low wages. She is a cook, not because she knows anything about cookery, but because she prefers the kitchen-fire to scrubbing floors, polishing grates, or making beds. A cook who can boil a potato and dress a mutton-chop is one in a thousand.’ Such very plain cooks will always exist for dyspeptic purposes, while those who are in authority over them remain ignorant of an art which, however much it may be slighted, exercises a crowning influence over health and happiness. Eat we must; and it is literally a subject of vital importance whether what we eat be properly adapted for healthful digestion or not.