by its action will deprive them of their fine green colour.  When this is effected, the whole may be put in contact with a heat that will enable the operator to reduce it to a fine powder.  And in order to keep it with its virtues perfect, it will be necessary to deprive it as much as possible of the influence of air and light.  Hence it is preserved in close glass bottles which are coated, and also placed in a dark part of the elaboratory.  Now, it is necessary that all plants intended to be used in a dried state, should be prepared and protected in a similar manner; and although it may be considered as a superfluous trouble, so far as regards the more common kinds, particular attention should be paid to these, when a small quantity is a dose, and an over-dose a certain poison.

Other kinds of vegetables require a certain degree of fermentation, as Tobacco.  The prinicpal art of preserving it consists in this operation being duly performed; for which purpose, as soon as the leaves of the herb are fit, the foot-stalks are broken, and the leaves left on, in order for the moisture in part to be evaporated.  Afterwards these are gathered and tied in handfuls, and hung up in the shade to dry; and when sufficiently divested of moisture, the bundles are collected together and laid in large boxes or tubs, in which these are fermented, and afterwards taken out again and dried; when it is found fit to pack up for the market.

The properties of Stramonium, which has been so much recommended for curing asthma, consist pricipally in the aroma, which is only to be preserved in a similar manner:  and I have found from experience, that if the leaves are separated from the plant in a manner similar to that of tobacco, and the rest of the plant, noth roots, stalks, and seed-vessels, be slit and sufficiently dried in the sun or in an oven, and the whole fermented together, a very different article is the produce than what it is when dried in the usual way, and left entirely to the chance influence of the atmosphere.

In the common operation of hay-making it may also be observed, that the continued turning it over and admitting its parts to the action of the sun and the air, is for the purpose of getting rid of the watery particles contained in it; and the quicker this is done, the better it is.  And although this operation is so essentially necessary, yet care should be taken at the same time, that it be not made too dry, so as to prevent a due degree of fermentation being allowed to take place in the rick.  And it may be observed that the best grasses, or other plants used for hay, if made too dry, so as to prevent the natural fermentation which their proper juices will excite, can never make either palatable or nutritive food for cattle.  Neither can the same be effected if the article is used in too small quantities.  It should be observed, that herbs of all kinds should be gathered for peserving when in full bloom; but when roots or barks are recommended, these should be collected in the autumn months.  The principles laid down for preserving dried plants generally, will apply to these parts also.