Alembic is particularly used in the alchemical context and along with the crucible and retort it is used to symbolise the the tranformative work of the soul.
This quote is from
http://www.levity.com/alchemy/vessel.html The final interior vessel I would like us to consider is that of the Still. When we try to experience our inner world though this symbol, we should have a sense of extracting an essence out of one of the interior processes, purifying and gathering it within our being so that it becomes an inner source we can touch upon at will. This alchemical operation to some extent corresponds in our everyday outer consciousness to the way in which an experience of coming to an understanding of some aspect of our world can entirely transform our way of interacting with it. For example, our initial reaction to a new piece of technology or an unfamiliar task, is tentative and fraught with difficulties we project upon this device or task. If we can eventually understand just how the device works or gain a picture of the movements needed to accomplish the task, then our way of using the device or of undertaking the task becomes entirely transformed.
Similar processes take place in respect to our interior life through the exercises of inner distillation, though this works on a more subtle plane. Here we take some particular positive quality of our being, such as our creativity, or our sensitivity to others, or our ability to think deeply and clearly, and we find some symbols that capture (or at least envelope) the essence of this quality. We then place these into our interior Still and in our meditation begin to allow these symbol patterns to flow together. At some point in the inner work, we should sense some essence of this process begin to rise out of and separate itself from the specific symbols and feelings connected with this quality. If we encourage this process we can have the inner experience of elevating this essence and allowing it to collect in the upper part of our soul. It then becomes a Tincture.
If, say, we choose to work upon our creativity through this exercise, we place into our interior Still, our understandings of the source of our creativity, picturings of our previous creations or our work in progress, memories of the emotional currents associated with our creative experiences, more universal symbols of creativity, and so on. In a meditative work on this facet, which will take many sessions to bring to fruition, we evoke all this material in our interior Still and attend closely to the processes and changes taking place there. For example, at one point we will experience the 'polarity flipping' of various symbols. We might, say, initially believe our creative impulse lies entirely in the quest for some ideal form, and experience this ideal image flipping (instantaneously interchanging) with its antithesis, some ugly shapelessness, or cycle of metamorphoses, producing disturbing patterns within our being. This stage will eventually resolve and we will find some symbol or feeling-perception that captures the essence of our creativity (or whatever we have chosen to work with) emerging out of the meditative material. If we nurture and sustain this essence, then we can allow it to rise up within our soul and we will feel it remaining as a kind of tincture in our inner world. If this tincture becomes fixed within our being then we can later draw upon it at will. What we find then is that a part of our inner forces retains an echo of all the meditative work we undertook at that time, and we can reconnect with this reservoir whenever we wish. So in the case of creativity, once we possess this inner tincture, then if we have some difficulties (or a block) over some particular piece of creative work, we will find that evoking the inner tincture of this experience, will put us deeply in touch with the ground of our creativity and may enable us to resolve our present problem.
Of course, such exercises are never entirely completed, as we ourselves are changing all the time in response to ongoing experiences, but working with our interior Still will be found invaluable in putting us in touch with the sources of our positive qualities. In alchemical terms the processes associated with the Still include those of Distillation, Exaltation, Fixation, Projection, Multiplication, Quintessence, etc.
