with continuing reference to fig1 and 2 it will be noted that side 60 also has three integrally formed connectors 68 70 and 72 each of which as best seen in fig6 comprises a pair of laterally spaced supports 74 76 and a snap fitting latch 78 in a similar manner side 64 has a series of connectors 80 82 and 84 and as illustrated in fig1 and 2 are displaced from the positions which would otherwise be directly opposite the connectors 68 70 and 72 in side 60 using the preceding description as a reference it will also be noted that side 62 has a series of latch holes 62a 62b and 62c and a series of connectors 96 98 100 likewise side 66 has a series of latch holes 66a 66b and 66c and a series of connectors 108 110 112 the latch holes 62a 62b and 62c in side 62 are displaced from the latch holes 66a 66b and 66c in side 66 in the manner previously explained in a similar manner the connectors 96 98 and 100 on side 62 are displaced from the connectors 108 110 and 112 on side 66 fig5 illustrates how two illustrative liquid contact plates are interconnected by bringing two sides of the plates together which have displaced connectors and latch holes and latching one side to the other in fig5 side 120 of illustrative liquid contact plate 122 is illustrated as having a series of connectors 124 126 128 formed in the manner of fig6 and with respective latch members 132 134.