Ch.up.6.5.1.S.B-Food, when eaten, becomes divided in three ways. The grossest
portion of the food turns into faeces. The medium constituent becomes flesh. The
subtlest part, having reached the heart, enters into the fine nerves named hitaa,
becomes transformed into the mind-stuff and nourishes the mind. It therefore follows
that the mind is made of matter. It is not considered as eternal and partless as defined
by the Vais'eshikas. (It is of the size of the body- madhyama parimaaNa). Ch.up.6.5.2.S.B--- Water (or any liquid) when drunk becmes divided in three ways.
The grossest portion becomes urine. The medium constituent becomes blood. The
subtlest part becomes the vital force (praaNa). Ch.up.6.7.1 says-"The vital force is
made up of water. It will depart from him who does not drink water".

    Ch.up.6.5.3.S.B-Butter, oil, etc, when consumed, become divided in three ways.
The grossest portion becomes bone. The medium constituent becomes marrow, the
greasy substance inside the bones. The subtlest part becomes the (subtle) organ of
speech (vaak). It is a well -known fact that by the consumption oil, butter and the
like, speech becomes clear and powerful. Ch.up.6.5.4.S.B-Therefore the mind is
made of food, the vital force is made of water and speech is made of tejas or fire
(i.e. butter, oil, etc).