How to read a 300-year-old letter without opening it

(Subscribe to Science For All, our weekly newsletter, where we aim to take the jargon out of science and put the fun in. Click here.) In 1926, a seventeenth-century trunk containing over 2000 unclaimed letters was bequeathed to the Dutch postal museum. The letters were closed using an ancient technique called letterlocking, in which the writing paper is intricately folded and secured to become its own envelopes. Now an international team of researchers has virtually unfolded and unlocked the contents of one of the letters and the findings were published on Tuesday in Nature Communications.