274 THE FLOEAL WOELD AND GAEDEN GUIDE. 



and in a condition to resume their functions immediately. The 

 value of such treatment to exhausted plants can hardly be over- 

 rated, and will often be found the turning-point between failure and 

 success. Plants which are merely transplanted from one part of a 

 garden to another are always benefited by the application of a few 

 gallons of water at their removal. The best time to apply it is 

 when sufficient soil has been thrown in to fairly cover the roots. If 

 applied then the mould is well washed in among the fibres, and by 

 filling in the remaining soil upon the wetted portion, evaporation is 

 checked, and the moisture secured to be gradually appropriated by 

 the plant. Mere surface watering is of little avail, unless very care- 

 fully and liberally supplied. Newly-planted trees are, however, 

 often much benefited by mulching, and if employed as an auxiliary 

 to watering, a double advantage is afforded by it. 



(To be continued.) 



THE ODOURS OF PLANTS AND THE MODE OF 

 OBTAINING THEM. 



|HE exquisite pleasure derived from smelling at fragrant 

 flowers would almost instinctively induce man to 

 attempt to separate the odoriferous principle from 

 them, so as to have the perfume when the season 

 denies the flowers ; and thus we find the alchemists 

 of old torturing the plants in every way their invention could devise 

 for this end. Their experiments were not wholly unsuccessful, and 

 indeed upon their foundation the whole art of perfumery has been 

 reared. Besides the uses in perfumery, the essential oils (the 

 matters to which the odour of the plant is due) are used by drug- 

 gists to cover the bad taste of medicines. Peppermint, coriander, 

 and cassia are much used for this purpose, and as the sense of smell 

 has much to do with taste, their utility is obvious ; by closing the 

 nostrils, many very nasty physics may be swallowed without tasting, 

 particularly rhubarb. We here see the advantage of the domestic sub- 

 terfuge of "a little peppermint " with a home "dose of castor oil," or a 

 peppermint lozenge before the " cup of salts and senna." Without 

 recapitulating those facts, which may be found diffused through 

 nearly all the old authors on medical botany, and works of this 

 character, we may state at once the mode of operation adopted by 

 the practical perfumer of the present day for preparing the 

 various extracts of essences, waters, oils, etc., used in his calling. 

 The processes are divided into four distinct operations. 



1. Expression, or the squeezing the odour-giving part of the 

 plant between two metal plates, which are generally made hot 

 (though sometimes cold, and hence the term " cold-drawn "), and 

 forced together by a powerful screw. This process is only adopted 

 where the plant is very prolific in its oil, i.e., odour. 



2. Distillation. — The plant, or part required, is placed in a 



