Vol. XIII. No. 307 



THK AGRICULTURAL NEWS. 



35 



application of these matters to agricultural science are 

 p: rticularly clearly dealt with in a paper by Wood and 

 Stratton.+ 



Turning to special consideration of variability in 

 relation to commercial samples in agriculture, we see 

 that it is not always the case that a dependable system 

 can be applied, owing to the circumstance that many 

 factors which determine quality cannot yet be con- 

 veniently expressed in figures. It is, however, interest- 

 inu to observe that in cases where they can, as in the 

 sale of snear or citrate ot lime, the material is compara- 

 tively homogeneous, and consequently little difficulty is 

 exiierienced in the matter of sampling. It is worth 

 reflecting, too, that the object in agricultural manufac- 

 turing is to turn the heterogeneous into the homoge- 

 neous. As already intimated, the denree of dependency 

 th'Jt can be placed on a fixed c|uantity of sample 

 requires investigation in the rubber industry, and in 

 the case of the cacao trade too. That is because 

 the plantation manufacture of these products does 

 not lead to perfect homogeneity. If the price 

 obtained for produce varied entirely with its real 

 quality, and was not affected by fluctuations in the 

 demand of the consumer, scientific valuation would be 

 likely to become more general than it is. It would 

 be interestint; to know e.vactly the minimum quantity 

 of lint that must be taken from a bale of cotton for the 

 determination of the true average value of the whole. 

 The valuation of cotton, depending as it does upon 

 several measurable physical jiroperties. seems certainly 

 capable of scientific investigation. The same holds 

 good for fibres in general, as well as in the case of 

 other classes of products. 



In drawing our considerations to a close, we may 

 fittingly conclude with an appeal regarding the present 

 subject in relation to agricultui-al education. It has 

 been emphasized in this journal that agricultural bias 

 can be given in rural schools to subjects other than 

 natural science. Of such instances where this can be 

 done, the present one of agriculture in relation to 

 mathematical principles cannot be said to be the least 

 in importance. 'Ihe future will probably show that it 

 will at all events have to occupy a very important posi- 

 tion in the curricula of agricultural colleges, and 

 a preliminary grounding in the principles of the subject 

 during latter years at school should sensibly assist the 

 student to appreciate its application to practical 

 matters in after-life. 



t T. B. Wo.ul ami F. J. M. Stnittoii:"TIie Interpretation 

 fpf Experiiiicntjil Ttcsnlls. Joniiial of Aijrinilturcd Science, 

 V>.1. Ill, p. 417. 



VEGETABLE OILS. 



ESSENTIAL OILS USED IN PERFUMERY- 



Id looking through the list of the botanical sources 

 of the essential oils used in scent-making, which are presented 

 in an interesting paper read before the Royal Society of Arts, 

 and published in that .Society's Journal of December 5, 1913, 

 one is struck b)' the large number of plants familiar in the 

 West Indies, wfiich are important sources of many of the 

 common jierfumes. The so-called floral series, for instance, 

 include.* the jasmine, rose and orange (lower; oils derived 

 from the grasses like citronella and lemon grass oil come from 

 species of Cymbopogon; the citrine series, as the name 

 implies, are got from oranges and lemons; the series of spices 

 are derived from Cassia, cinnamon, cloves and nutmegs. 

 Important in the perfumery industry are the wood 

 series which includes sandal wood and cedar wood. Lastly, 

 the fruit series contains well-known plants like the bitter 

 almond, vanilla and the Toncjuia bean. 



Mr. J. C. IJmney, F.C.S., the writer of the paper, 

 makes the remark that the classification just referred to, 

 although useful botanically, is generally superseded by a 

 classification according to the main constituents of the oils 

 for pharmaceutical purposes. From the classification which 

 is given we see, for instance, that plants like clove, pimento, 

 cinnamon and bay are characterized by their eugenol contents, 

 whereas citronella oil, citrus oils and Cassia, are known by 

 the aldehydes they contain. 



Towards the middle of the paper Mr. I'mney referred 

 to the agricultural side of the essential oil industry. The 

 isl;\nd of Reunion is producing large quantities of geranium 

 oil; Paraguay exports a great quantity of pettigrain oil; 

 whilst from the Philippine Islands, Europe is receiving large 

 shipments of the finest ylang-ylang oil, and from Madagascar 

 and the neighbouring islands also, extremely tine ylang-ylang 

 :ind other oils are shipped. In connexion with lemon grass oil, 

 it is pointed out that this is produced in the East Indies, 

 the Malaya Peninsula, Hurma and the West Indies, and that 

 it appear.< to be in danger of being overproduced, prices 

 having fallen very much during the last few years. The 

 marvellous protective power, it is interesting to note, of 

 lemon grass in the matter of keeping off the tsetse lly, haa 

 li'd to its cultivation and to the distillation of the oil in 

 Uganda, a fair amount having already been marketed from 

 that region. It is stated that it was formerly proposed that 

 the West Indian lemon grass oil was less soluble than that 

 obtained from the East Indies; this does not appear now to 

 be uniformly the case. 



.Space will not allow further reference to the interesting 

 information which the paper contains. But in conclusion it 

 will be well to point out that those who took part in the 

 discussion following the reading of the paper were of opinion 

 that there is decided scope in the colonies for an extension 

 of the area under the cultivation of plants yielding essential 

 oils. 



This article cannot be concluded without some expres- 

 sion of surprise that Dr. T. A. Henry of the Imperial 

 Institute should have made the statement in connexion with 

 starting experiments in the colonies in relation to essential 

 oils, that 'an attempt had been made in the West Indies to 

 grow limes and oranges, but the yield of these fruits was 

 poor, while the class of labour available was unsatisfactory.' 

 As a matter of fact citrus cultivation is one of the most 

 prosperous of the West Indian agricultural industries. 



