Today is Uposatha Day...and Texas is very very cold now 51F !!
Abhidhamma View: Defining Dhaatu
[Presented by Dr.Tep Sastri @ sariputtadhamma/JTN]
Vism. p. 344-348 (excerpt):
27. Now comes the description of the development of the definition of the four elements, which was listed as the one defining next to the perception of repulsiveness in nutriment (III.105). Herein, defining (vavatthaana) is determining by characterizing individual essences . [The compound] catudhaatuvavatthaana (four-element defining) is [resolvable into] catunna.m dhaatuuna.m vavatthaana.m (defining of the four elements).
Attention given to elements,the meditation subject consisting of elements and defining of the four elements all mean the same thing . This is given in two ways: in brief and in detail. It is given in brief in the Mahaasatipa.t.thaana Sutta (D II 294), and in detail in the Mahaahatthipadopama Sutta (M I 185), the Raahulovaada Sutta (M I 421), and the Dhaatuvibhanga Sutta (M III 240).
[Note 19]˜By characterizing individual essences: by making certain (upadhaara.na) of the specific characteristics of hardness, and so on. For this meditation subject does not consist in the observing of a mere concept, as in the case of the earth kasi.na as a meditation subject, neither does it consist in the observing of the colour blue, etc., as in the case of the blue kasi.na as a meditation subject, nor in the observing of the general characteristics of impermanence, etc., in formations, as in the case of insight as a meditation subject; but rather it consists in the observing of the individual essences of earth, and so on. That is why by characterizing individual essences is said, which means, by making certain of the specific characteristics of hardness, and so on(Vismmh.t 344).
28. It is given in brief in the Mahaasatipa.t.thaana Sutta, for one of quick understanding whose meditation subject is elements, as follows: Bhikkhus, just as though a skilled butcher or butcher's apprentice had killed a cow and were seated at the crossroads with it cut up into pieces, so too, bhikkhus, a bhikkhu reviews this body however placed, however disposed, as consisting of elements: In this body there are the earth element, the water element, the fire element, and the air element (D II 294).
29. The meaning is this: just as though a clever butcher, or his apprentice who worked for his keep, had killed a cow and divided it up and were seated at the crossroads, reckoned as the intersection of the main roads going in the four directions, having laid it out part by part, so too a bhikkhu reviews the body, however placed because it is in some one of the four postures and however disposed because it is so placed, thus: In this body there are the earth element, the water element, the fire element, and the air element. 
[Note 20] Herein, as regards earth element, etc., the meaning of element is the meaning of individual essence, the meaning of individual essence is the meaning of voidness, the meaning of voidness is the meaning of not-a-living-being. So it is just earth in the sense of individual essence, voidness and not-a-living-being that is the element; hence it is earth element; so too in the case of the water element, and the rest. The earth element is the element that is the foothold for the conascent material states. Likewise the water element is the element of their cohesion; the fire element is the element of their ripening; and the air element is the element of their conveyance and distension.
[METHOD OF DEVELOPMENT IN BRIEF]
39. As regards the method of development here, however, to discern the elements in detail in this way, The head hairs are the earth element, the body hairs are the earth element, appears redundant to a bhikkhu of quick understanding, though the meditation subject becomes clear to him if he gives his attention to it in this way: What has the characteristic of stiffenedness is the earth element, what has the characteristic of cohesion is the water element, what has the characteristic of ripening (maturing) is the fire element, what has the characteristic of distending (supporting) is the air element. But when one of not over-quick understanding gives his attention to it in this way, it appears obscure and unevident, and it only becomes plain to him if he gives his attention to it in the first-mentioned way.
Love Buddha's dhamma,