Of invisible Writing.

L’tharge is first powdered and cast into an earthen pot chat hath water and unegacmix'd;boyl i:,and strain it,and keep it: then write letters with Citron Lem >n j-?ce rthese are added to them when they begin to dry. If you dip them in the iiq Wker r,they will appear dearly and very white. If womens brests or hands be we; in it,andyou sprinkle the said water upon them, they will grow white as Milk. Use it. I: arany time you want these, if you please,

A ftone dipped in vinegar will [hew the letters.

Make letters with Goats fat upon a stone ; when they are dry. they will cot be seen.If the stone be dipt into vinegar they presently come forth, and seem above the stone.But if you would have letters writ with water only, appear black, that you miy thebetter be provided,and more speedily for a voyage; beat Galls and Vitriol fi.ely,andstrew this powder on your paper : rub it with a cloth,and polish it well^hat so it maystick fast to the piper, and be like ic. Powder Juniper-gum, which Scriveners callVernish, and add it to the rest: when you would use it, write with water or spittle,and they will be black letters. There are many such Arcs; too tedious to relate.

Chap. II.

How letters are made v'tfible in the fire.

1 Shall shew the ways how letters are not made visible but by file j or not, unlesslight interpose, or may be read when they are burnt. But... To make letters visible by fire.

So we may bring forth letters written between the verses, and in the close settingtogether , or larger distances of syllables. Let the Epistle contain some void space,that the letters may not be seen ; and if this be intercepted, it will hardly be read.If you write with the juice of Citrons, Oranges, Onyons,or almost any sharp things,if you make it hpt at the fire , their acrimony is presently discovered t for they areundigested juices, whereas they are detected by the heat of the fire, and then theyChe w fort h those colours, that they would shew if they were ripe. If you write with% sowre Grape that would be black , or with Cervices; when you hold them to thefire, they are concocted , and will give the fame colour they would in due time giveupon the tree, when they were iipe. Juice of Cherries, added to Calamus, will makea green ; to sow-bread, a red: so divers juices of Fruits, will shew divers colours bythe fire. By these means,Maids sending and receiving love-Letters,escape from thosethat have the charge of them. There is also a kin de of Salt called Ammoniac; thispowdered and mingled with water , will write white letters, and can hardly be di-stinguished from the paper: but hold them to the fire,and they will shew black. Also,

Letters that cannot be read unless the paper be burnt.

For the mixrure will be white, and nothing will be seen ; but when it is burnt, thepaper will be black, and tt^eCharacters wist be white: Take the sharpest vinegar andthe white of an Egg ; in these steep Quick-silver, and stir it well; and with that mix-ture make Letters pn the paper; bum the paper in the fire,and the letters will remainnnbpmt; or make letters on the paper with ■©urn, pr any kind of Salt or Lime > these,being they cannot be seen at the fire , when the paper is burnt and made black, theywzjl appear white. If you will, you may, > -

. ' ; - > > k? t . "

Write letters that cannot be seen but by interpofition of fire. ! *

Do it thus : Mingle Ccruss, or some ether white colour, with GumTragantb,soaked, and of tViis mixture is made a matter of the fame colour with the paper, thatH cannot be discerned from it,nor cause suspicion: then this being put between thepye and the light of a candle, the eye cannot pals through where the letters are writ-tfen , and you shall see them darkly. This is by reason of theOpticks : for charpart of thick matter opposed against outward light;, hinders it, that the rays cannotcpme tp our sight j and so the prints of the letters are seen as a shadow;v..‘ T Chap;