The 2016 article by Michael Witty, entitled ‘Hooke’s Gravel was Struvite’1¹ is essentially a comparison of two microscopic observations, ancient and modern. The images of the two crystal types involved were obtained by what are described as ‘unmentionable’ observations and experiments. Robert Hooke, in his Micrographia, discloses investigations into substances collected from 17th-century urinals.2²

中文翻译：

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关于罗伯特胡克的“不可提及的观察”

Michael Witty 2016 年发表的题为“胡克的砾石是鸟粪石” ^{1 1}的文章本质上是对古代和现代两种微观观察结果的比较。所涉及的两种晶体类型的图像是通过所谓的“不可提及”的观察和实验获得的。Robert Hooke 在他的Micrographia中披露了对从 17 世纪小便池中收集的物质的调查。2 ²