\(\cos \theta  = \frac{{{T_{SA}} - {T_{SL}}}}{{{T_{LA}}}}\)

when water is on a waxy or oily surface

\({T_{SA}} < {T_{SL}}\cos \theta \,is\,negative\,i.e.,\)

\({90^ \circ } < \theta  < {180^ \circ }\)

\(i.e.,\,angle\,of\,contact\,\theta \,increases\)

\(And\,for\,\theta  > {90^ \circ }\,liquid\,level\,in\,capillary\,tube\)

\(fall.\,i.e.,\,h\,decreases\)