In prism, schism the m may have syllabic value; it then does the work usually performed by a vowel. We say [prizəm] or [prizm̩], where [m̩] is the sign for syllabic m.
[m] is written m or mm.
23. In the production of the lip stops the tongue plays no part, except by leaving a free passage; but it is active in the production of the stops we next have to consider. This is therefore the right place to give the names by which we designate the various parts of the tongue. We distinguish
the point,
the blade (above and behind the point when the tongue lies flat),
the front (yet further behind), and
the back; also
the ridge or dorsum (an imaginary line drawn along the middle of the top of the tongue from end to end), and
the rim (running all round the edge of the tongue when it lies flat).