Comments for the Editors: Dear Editor It is very important for the future of this field that fine experimental work of this sort be forced to use theoretical work that confronts the results of the experiments. To put it over simply, the authors show that in ionic solutions in nanochannels, "everything interacts with everything else". They then MUST NOT use a theory in which everything does not and cannot interact with everything else. Variational methods are used in many areas of physics for conservative systems exactly because they automatically (provided the math is done right) provide consistent descriptions of models and systems in which everything interacts with everything else. It is only recently that such methods have been generalized to NONconservative systems, but now, thanks to the work of Chun Liu (Penn State), more than anyone else, such a generalization is possible. For example, the full Navier Stokes equations can now be derived by a variational principle (not of course by the conservative variational principle itself). The authors must discard their patently INconsistent theory (despite their attempts at patching it up) and either USE a consistent treatment, or say that a consistent variational treatment is needed to analyze their results. Otherwise this paper can do much harm to understanding (which requires consistent experiments AND theory AND simulation) despite its superb experimentation and experimental advances ------------------------------------------------------------ begin_report The authors are to be congratulated on a major experimental advance and important discoveries that certainly warrant publication in Phys Rev Letters (in my view) once the theoretical treatment is corrected. As the authors show admirably, the nanochannel system is fully coupled, with fields of one type generated flows of another, if I can be forgiven the loose language. I write this way to avoid a long and tedious description of the couplings that the authors do much better than I could. The theory thus must deal with such couplings, and the THEORY MUST BE CONSISTENT (i.e., all variables must satisfy all the field equations of each type of field and all boundary conditions in all experimental situaitons). Otherwise, the theory is actually misleading and dangerous, because people will adjust parameters to force agreement with experiments, as situations change, instead of realizing that the need to adjust parameters is evidence that the theory is incomplete, inconsistent, and in those senses, wrong. Systems analyzed, and devices built with inconsistent theories will not work, except in special very lucky situations. The only way to be sure of this (in my view) is to use a variational treatment, where (as long as the algebra is done correctly) consistency is automatic. Of course, it is sometimes possible to guess a fully consistent treatment, but in that case THE THEORY MUST ACTUALLY BE SHOWN (BY MATHEMATICS ALONE AND NOT ARGUMENT) TO SATISFY ALL EQUATIONS AND BOUNDARY CONDITION UNDER ALL SITUATIONS. The following papers show the approach I am talking about and actually provide the equations and integration schemes needed to analyze the experiments of the authors. Eisenberg, B., Y. Hyon and C. Liu (2010). "Energy Variational Analysis EnVarA of Ions in Water and Channels: Field Theory for Primitive Models of Complex Ionic Fluids." Journal of Chemical Physics 133: 104104 Mori, Y., C. Liu and R. S. Eisenberg (2011). "A model of electrodiffusion and osmotic water flow and its energetic structure." Physica D: Nonlinear Phenomena 240(22): 1835-1852.