Under the weight of evidence. Unnatural death

This collection includes two interesting things by Lord Peter Uimzi-an aristocrat, an intellectual and a talented amateur detective.
not far from the hunting house of the older brother Peter Uimzi, Duke Denversky, captain Denis Katkart was found shot dead. A murder weapon belonging to the Duke was found nearby. To top it all the day before, the captain and the Duke seriously quarreled.
Against the Duke - all: from testimony to a good motive and evidence. But Peter Uimzi, who believes in the innocence of his brother, intends to find a real killer ...
It would seem that in the death of the fabulously rich lady Agatha Dawson there is exactly nothing suspicious: she was at a very advanced age and suffered from a serious incurable illness. So what alerted the usual provincial doctor who resolutely refused to sign a death certificate?
Peter Uimzi decides to find out the circumstances of the case and discovers that Miss Dawson is only the first of the victims of murders, sophisticatedly stylized as natural death