Details of Necheles’ “flat plate”, low-resistance pumpless dialyzer using flattened wide tubes of prepared peritoneum with glass tubes each end for connection to rubber tubing. The separate units Left) and their flattening supports were perfused with blood serially, whilst immersed in a bath of warmed, aerated dialysis fluid (glucose saline, or Locke’s solution). Up to 10 modules were used (right), giving a maximum dialysing surface area of 4 m2. From reference [29]. Note that the serial design is much less efficient than a parallel design such as that of Abel and colleagues, but this requires some form of complicated manifold