Berlin 22nd February 1828

Dear Professor,

While I certainly hope that my letter of 12 January and the postscript of 2 February have arrived, and I live daily, or better hourly, in the eager hope of receiving your reply, still I will not wait for it but rather write already again, because I cannot, so to say, hold my chemical water and must tell you that I can make urea without the help of a kidney or even an animal, neither man nor dog. Ammonium cyanate is urea. - Perhaps you still remember the experiment I carried out in that fortunate time when I was working with you, in which I found that whenever one tries to react cyanic acid with ammonia a crystalline substance appears which is inert, behaving neither like cyanate nor like ammonia. On leafing through my notebook this struck me again, and I supposed it possible that in combining cyanic acid with ammonia the elements might have come together in a different way, albeit in the same proportion, and thus perhaps a vegetable base or something of the sort might have been formed. Thus I recently performed a small experiment, appropriate to the limited time I have available, which I quickly completed and which, thank God, did not require a single analysis. - I obtained the supposed ammonium cyanate very easily by treating lead cyanate with caustic ammonia. One can also prepare it with silver cyanate and ammonium chloride. I obtained it in quantity beautifully crystallized and indeed in clear right-angled four-sided prisms. With acids no carbonic acid or cyanic acid was formed and with base no trace of ammonia. But with nitric acid there was formed a compound that crystallized readily in glittering leaves with a very acidic character that I was already inclined to regard as a new acid, since upon heating no saltpeter or nitric acid, but only a good deal of ammonia was formed -, when I discovered that upon saturation with bases nitrate salts and the original so called ammonium cyanate formed again, and could be recovered from alcohol.

Stockholm 7 March 1828

When one has begun his immortality with urine, there is every reason to end the trip to paradise in the same way. - and truly the doctor has found the proper path to achieve immortal fame. Aluminum and artificial urea, certainly two very different matters, following one another so closely, will, my Lord, be braided as jewels into your crown of laurels, and should the quantity of the artificial not suffice, one could easily make up the difference with a little from the chamber pot. Will one now succeed in moving into somewhat broader production (seminal vesicles being somewhat to the fore of the bladder), what masterful art to make such a tiny child in the laboratory of the technical school. - Who knows? It might be easy enough.[* ] - But now enough raillery, especially since I am in such a hurry to write discretely in the Annual Report. It is a truly important and beautiful discovery that the doctor has made, and it gives me indescribable delight to hear of it. It is a unique situation that the salt nature so entirely disappears when the acid and ammonia combine, one that will certainly be most enlightening for future theory

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Please greet the friends for me.

Greetings and friendship

Berzelius