pear tree log: I started this blog to keep my younger son, Jonny, in touch with life in Lincolnshire, while he spent a year working in China. That year turned into five! Now he is home and training to become a physics teacher. This is simply a patchwork quilt of some of the things I enjoy - life in rural Lincolnshire, our animals, friends, architecture, books, the gardens, and things of passing interest.

Friday, 16 December 2011

Top Secret Recipe - for Secret Agent Knatolee

I shall say this only once ... Secret Agent Knatolee ...remember this post will self-destruct in 10 seconds...your younger self longed for secret ink so I have trawled my books and found some very old (the book is dated 1755) versions of secret ink for you.

  • If you dip your pen in the juice of a lemon, or of an onion, or in your own urine, or in Spirits of Vitriol and write on clean paper whatever you intend, it shall not be discerned till you hold it to the fire, and then it will appear legible. 
  • And, if with any of the aforementioned you write on your skin, as on your arm and back of your hand, etc, it shall not be seen till you burn a piece of paper and with the ashes rub on the place and then it will appear very plain; and this I have experienced and try'd, and therefore can say Probatum est.
  • Another way is when you write a letter that you intend it shall not be discovered, but to those you think fit first to write your thoughts on one side of your letter with black ink, as usual, (but it ought to be on thin paper) and then on the contrary side, go over the said matter that you would have secret, with a clean pen dipp'd in milk and that writing shall not be read without holding it to the fire, as mentioned above, and then it will appear legible in a bluish colour.
  • Or, you may write to your friend in proper sense with common ink, and let the lines be at so commodious a distance, that what you intend to be secret may be written between them with water, wherein galls have been steeped a little time (but not long enough to tincture the water) and when dry nothing of the writing between the said lines can be seen, but when it is to be read, you must with a fine hair pencil dipp'd in Copperas Water, go between the said lines and so you make it legible.  
  • Note:  this way will give no ground for suspicion, because the letter seemeth to carry a necessary sense in those lines that are set at such a proper distance...
So, Secret Agent Knatolee - you have no excuses now.

To work!


  1. unfortunately...people today dont write letters in ANY form x

  2. Hi John, It is a shame - I recently discovered a large cache of letters which my mother had written to Aged Aunt and my beloved Uncle John.

    They were sent 50 years ago when we were living in Hong Kong, the later ones sent when we lived in the Western Isles. Aged A didn't want them, so I brought them home and (at first feeling a bit uncomfortable at reading someone else's letters) but then the usual delight I have in reading handwritten things took over. My mother's handwriting 'chatting' about things which I recall from all those years ago. I cherish them.

    Somehow, I can't quite imagine a collection of email or text messages ever giving the same pleasure to someone in time to come.

    PS I also came across a collection which the child Elaine had sent - embarrassing doesn't cover it.

  3. I have always wondered why your writing desk has three bottles of ink (next to the decanters). Now I know. Blue, black and "invisible yellow".

    Atcherly I remember you telling me about writing with onion juice when I was a brat-ling. It worked too.

  4. Hello Ian,
    So you did listen to your older sister occasionally! I must test all those letters for invisible ink - actually, I really do have an 18th Century letter which has exceptionally wide line spacing... I must away to the laboratory!

  5. OH no, how could I have missed this when you originally posted it!?!?!?! Belated thanks for the excellent instructions!

    1. Hi Knatolee, My goodness, I had completely forgotten about this - good job I didn't do it in invisible ink.


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