On September 5, 1809, the Bishop of Lincoln - George Pretyman-Tomline, one of Pitt's executors - wrote from his residence at Buckden Palace to an anonymous "Sir," answering some questions posed to him regarding Pitt's health, and cause of death. It seems questions were also raised regarding the nature of Pitt's exorbitant debts given his simple tastes, as well as inquiries about the whereabouts of Pitt's papers.
“I received your Letter on Saturday, & now take the earliest opportunity in my Power of answering the questions contained it it. I do not consider that any particular disorder was the cause of Mr. Pitt’s death. I observed a gradual decline of health & strength for several years. His [Pitt’s] appetite was far less than it used to be, & he was not equal to any considerable degree of exercise. I believe that I noticed this alteration earlier than any other of his Friends & was more alarmed by it. In the Autumn of 1805 he had been very unwell - it was recommended to him to go to Bath. he had found great benefit in a former illness from the Bath Waters. He went thither in December - soon after his arrival he had a fit of the Gout, & thought himself better for a short time. But the Gout appeared again during his stay at Bath, & he never afterwards recovered even a moderate degree of strength. his appetite almost entirely failed, & it being thought improper for him to drink the Bath Waters, he left Bath, & such was his weak state that he was 4 days in reaching his house at Putney. At Putney I saw him the day after his arrival there, & was much struck by the evident change which had taken place. I remained with him in the house which I did not leave till after his death. - that is, from the Sunday 1/12 [January 12th, 1806] to the Thursday sennight [January 23, 1806] following. He [Pitt] complained of a peculiar pain in his stomach, & seemed himself to think that some vital part was affected. I requested the Physicians to pay particular attention to him closely upon the subject of this pain, & they afterwards assured me that nothing was to be apprehended from it. He declined gradually till Nature was quite exhausted - he was compleatly worn out in the service of his Country.
About 8 o’clock on Wednesday Morning Jan ye 22 I informed him of his danger. He asked for Pen Ink & Paper that he might make his Will. It was very short, but I am unable to mention its Contents from memory as you may easily attain a Copy of it from the Commons. He appointed Lord Chatham & myself his Executors & to look over his Papers - at the same time he said, “I wish a thousand or fifteen hundred a year to be given to my Nieces if the Public should think my long services deserving it, but I do not presume to think I have earned it.”
I have no Papers at Buckden which would enable me to state Mr Pitt’s exact circumstances at the time of his death, nor indeed could I do so even with the assistance of accounts which are in Town, as there are some matters which are still unsettled. I therefore submit to you whether it would not be sufficient (& in any case better) to state generally that Mr Pitt’s original Private Fortune was 1000£ to which had been added a Legacy of 3000£ left to him by the late Duke of Rutland - that immediately upon his decease it was determined that some persons should examine into the state of his affairs, & after an estimate had been made of the amount of his debts & the probate produced of his effects 40000£ was voted by Parliament towards the payment of his Debts. I conceive that the inadequacy of the salary annexed to the situation he held to cover its necessary expenses may be noticed. Improvements at Hollwood & at Walmer were his chief amusements, & those were the only expenses which his enemies could consider as unnecessary - if perhaps too great inattention to household expenses be excepted, no other cause can be assigned for his embarrassments, & surely the nature of his amusements must be acknowledged as highly honourable to his Character. I thank you for your attention to my wishes respecting the passage you allude to, & sincerely rejoice to you [that] my important & interesting Wish is so nearly compleated. I shall be very impatient to see the Last Volume.” 
Perhaps Tomline was addressing one of Pitt's early biographers?
1. George Pretyman-Tomline (the Bishop of Lincoln) to "Sir," September 5, 1809. Ipswich Record Office, Pretyman MSS. HA 119: T99/27 f. 55.