In the smaller distilling plants, in New South Wales particularly, it has become customary to generate the steam in the vessel in which the leaves are packed. A very general method is to employ one or more of the common square 400-gallon iron tanks, to insert a grating of some kind at about 8 inches from the bottom to support the leaves, and to fill the space below with water. The tanks are placed upon a suitable foundation and the fires lighted below. When the water boils the steam passes through the leaves, carrying the oil with it. The condenser and still attachments take various forms, but all are constructed with some regaid to the main principles of condensation. In the more simply constructed plants, particularly in localities where water is abundant, the condensation is brought about by laving a sufficient length of pipe from the still, in a running stream if possible, bending the end of the pipe outwards through some protection, and collecting the condensed water and oil in a receiver in which the oil separates, and is drawn off either automatically or otherwise.

In simple distilling plants of this nature no provision is usually made for unloading the spent leaves by mechanical means, this operation being performed by manual labour, so that, with a still of this description, it is evident that a minimum of result is obtained with a maximum of effort; but this primitive method of distillation will continue to be employed because the plant is cheap, easily dismantled for removal, and can be worked by one or two men, by families, or by small communities.

The lid attachments to these tank stills are made in various ways, the most common being to remove the top, and rivet a right-angled flange around the outside. The lid is a flat sheet of iron, and between this and the flat surface of the flange the joint is made, by inserting packing of some sort, either with clay or without, and fastening the whole with stout steel clips. Another method is to have the flange turned inwards, and to fasten stirrups on the outside of the tank. The lid is a flat sheet of iron in this case also, and the joint made steam-tight in the usual way and fastened tightly by the aid of wedges.

It was considered at one time that the correct arrangement for a Eucalyptus oil still must include a copper still-head, to allow of easy exit of the steam from the tank to the condenser, but in the majority of cases this copper outlet is now discarded, as it was found to be unnecessary and costly. It must be remembered, too, that in nearly every case Eucalyptus oils contain free acid, and this, when present in sufficient amount, attacks the copper, the dissolved portion being conveyed into the oil, giving it a green colour. How injurious this may be is seen from the results we have recorded under E. cincrea. The outlet for the steam is now made in a simple manner by inserting a 2 or 3 inch iron pipe through the side of the tank just below the top. No difficulty is experienced, and practically all the oil is obtained from the leaves in this way.