____________

[Footnote 1: See Dr B.N. Seal's _Positive Sciences,_ pp. 104-108, and
_Nyayakandali_, pp. 33-34, "_S'arirarambhe paramanava eva kara@nam na
s'ukra-s'onitasannipata@h kriyavibhagadinyayena tayorvinas'e sati
utpannapakajai@h parama@nubhirarambhat, na ca s'ukras'onitaparama@nuna@m
kas'cidvis'e@sa@h parthivatvavis'e@sat....Pitu@h s'ukra@m matuh s'onita@m
tayos sannipatanantara@m ja@tharanalasambandhat s'ukra-s'onitarambhake@su
parama@nu@su purvarupadivinas'e sama@nagu@nantarotpattau
dvya@nukadikrame@na kalalas'arirotpatti@h tatrantahkara@napraves'o...tatra
maturahararaso matraya sa@mkramate, ad@r@s@tavas'attatra
punarja@tharanalasambandhat kalalarambhakaparama@nu@su
kriyavibhagadinyayena kalalas'arire na@s@te samutpannapakajai@h
kalalarambhakaparama@nubhirad@r@s@tavas'ad
upajatakriyairaharaparama@nitbhi@h saha sambhuya
s'arirantaramarakkyate."_.]

329

In the case of poly-bhautik or bi-bhautik compounds there is
another kind of contact called _upa@s@tambha_. Thus in the case of
such compounds as oils, fats, and fruit juices, the earth atoms
cannot combine with one another unless they are surrounded by
the water atoms which congregate round the former, and by the
infra-atomic forces thus set up the earth atoms take peculiar
qualities under the impact of heat corpuscles. Other compounds
are also possible where the ap, tejas, or the vayu atoms form the
inner radicle and earth atoms dynamically surround them (e.g.
gold, which is the tejas atom with the earth atoms as the surrounding
upa@s@tambhaka). Solutions (of earth substances in ap)
are regarded as physical mixtures.

Udayana points out that the solar heat is the source of all the
stores of heat required for chemical change. But there are
differences in the modes of the action of heat; and the kind of
contact with heat-corpuscles, or the kind of heat with chemical
action which transforms colours, is supposed to differ from what
transforms flavour or taste.

Heat and light rays are supposed to consist of indefinitely
small particles which dart forth or radiate in all directions rectilineally
with inconceivable velocity. Heat may penetrate through
the interatomic space as in the case of the conduction of heat, as
when water boils in a pot put on the fire; in cases of transparency
light rays penetrate through the inter-atomic spaces with _parispanda_
of the nature of deflection or refraction (_tiryag-gamana_).
In other cases heat rays may impinge on th