In a recent paper by H. Nakayama and C. Hayashi [Thermochim. Acta 253, 77 (1995)] it has been suggested that the structural organization of water molecules around a hydrophobic molecular ion changes when the solution is subjected to different thermal treatments. In this letter we report a series of neutron diffraction measurements that show no significant difference in the total structure factor of the solution for the case of tetrabutylammonium chloride in deuterated water.