Linné on line 
Mathematics in Linnaeus’ time "our honest Klingenstierna" Death and grieving
Death and grieving
Owing to his poor health, Klingenstierna had to give up his position at court in 1764. Even though he was bedridden for long periods of that year, he did not abandon mathematics, especially not geometry. There are many manuscripts preserved in which he attempts to restore theorems that were assumed to have been included in one of Euclid's missing, but talked about books, Porism. A "definitive" reconstruction of the book was carried out in 1860 by Michel Chasles.
Klingenstierna died on October 26, 1765.
Strömer writes:
"In the evening when he was about to sit down at the table with his beloved daughters, he cried out, invoked the name of Jesus, his Saviour, and fell into the arms of his elder daughter, who had run to his aid, whereupon this precious and rare life was already ended."