MATTER & FORM
This is meant to be an introduction to the concept of matter and form relevant to sacramental validity.
The following is an extract from the Catholic Encyclopedia. In the Handbook of Moral Theology you will find matter and form covered under each individual Sacrament.
http://www.newadvent.org/cathen/13295a.htm
(5) Matter and Form of the sacraments
Scholastic writers of the thirteenth century introduced into their explanations of the sacraments terms which were derived from the philosophy of Aristotle. William of Auxerre (d. 1223) was the first to apply to them the words matter (materia) and form (forma). As in physical bodies, so also in the sacramental rite we find two elements, one undetermined, which is called the matter, the other determining, called the form. For instance, water may be used for drinking, or for cooling or cleansing the body, but the words pronounced by the minister when he pours water on the head of the child, with the intention of doing what the Church does, determines the meaning of the act, so that it signifies the purification of the soul by grace. The matter and form (the res et verba) make up the external rite, which has its special significance and efficacy from the institution of Christ. The words are the more important element in the composition, because men express their thoughts and intentions principally by words. "Verba inter homines obtinuerunt principatum significandi" (St. Augustine, De doct. christ.", II, iii; ST III:60:6). It must not be supposed that the things used for the acts performed, for they are included in the res, remarks St. Thomas (ST III:60:6, ad 2) have no significance. They too may be symbolical, e.g. anointing the body with oil relates to health; but their significance is clearly determined by the words. "In all the compounds of matter and form the determining element is the form: (ST III:60:7).
The terminology was somewhat new, the doctrine was old; the same truth had been expressed in former times in different words. Sometimes the form of the sacrament meant the whole external rite (St. Augustine, "De pecc. et mer.", xxxiv; Conc. Milev., De bapt.). What we call the matter and form were referred to as "mystic symbols"; "the sign and the thing invisible"; the "word and the element" (St. Augustine, tr. 80 in Joann.). The new terminology immediately found favour. It was solemnly ratified by being used in the Decree for the Armenians, which was added to the Decrees of the Council of Florence, yet has not the value of a conciliar definition (see Denzinger-Bannwart, 695; Hurter, "Theol. dog. comp.", I, 441; Pourrat, op.cit., p. 51). The Council of Trent used the words matter and form (Sess. XIV, cap. ii, iii, can. iv), but did not define that the sacramental rite was composed of these two elements. Leo XIII , in the "Apostolicae Curae" (13 Sept., 1896) made the scholastic theory the basis of his declaration, and pronounced ordinations performed according to the ancient Anglican rite invalid, owing to a defect in the form used and a lack of the necessary intention on the part of the ministers. The hylomorphistic theory furnishes a very apt comparison and sheds much light on our conception of the external ceremony. Nevertheless our knowledge of the sacraments is not dependent on this Scholastic terminology, and the comparison must not be carried too far. The attempt to verify the comparison (of sacraments to a body) in all details of the sacramental rite will lead to confusing subtilities or to singular opinions, e.g., Melchior Cano's (De locis theol., VIII, v.3) opinion as to the minister of Matrimony (see MARRIAGE; cf. Pourrat, op.cit., ii).
Put simply:
MATTER = (Material Used {eg. water} & Actions)
FORM = (Words Which Give Precise Meaning To The Matter)