7b 



The author states in his introduction that "' the geology of the 

 British Isles is. to a great extent, an epitome of the geology of the 

 world which shows us that the books will be valuable to Tropical 

 Students as to those of other climes. It is to he highly recom- 

 mended for the use of classes in practical Agriculture. 



The practical Agriculturisl will be all the more fitted to compete 

 with his fellows if hi- knows the elements of Botany, Entomology. Phy- 

 sics, Chemistry. Mechanics. Hydraulics, Natural Historyand Geology, 

 and no simpler or better work for obtaining information on the latter su b- 

 jectcan be found than Marr's Agricultural Geologj . Methuen & Co. 1903. 



619. -SESAMUM INDICUM. 



Enquiry has come to bandfor seed of this plant for the purpose 

 of Manufacturing Oil. In good seasons the plant appears to thrive 

 very well, and it is quite possible that it would prove a remunerative 

 crop, and one specially suited to small cultivators. A trial plot will 

 he opened at St. Clair during the ensuing season. It is hoped that 

 reliable information will be to hand us to prices in time for the next 

 issue of the Bulletin. 



620. PRODUCTION AND MANUFACTURE OF 

 VANILLIN AS A SUBSTITUTE FOR VANILLA. 



[mperi \l Institute, 

 (South Kensington, London, s.VV., 



Vanillin is the constituent to which vanilla owes its aroma and 

 flavour. It was discovered in 1858 by Gobley, and was subsequently 

 investigated by a number of chemists, notably by Tieman, who first 

 prepared it artificially from coniferin. a glucoside found in certain 

 coniferous plants. Since that time a large number of processes for 

 the artificial preparation of vanillin on a commercial scale have been 

 devised. The first of these to meet with commercial success was that 

 of De Laire (English Patents: 1890 No. 17547 : 1891 No. 17137), 

 who used as a starting point eugenol, the substance to which oil of 

 cloves owes its characteristic odour. De Laire's process, either in its 

 original form or slight lv modified, was worked in France by De 

 Laire & Co.. and in Germany by Haarmann and Reimer during the 

 period 1891-1896, apparently under an agreement to avoid competition 

 in prices. About 1897, however, a period of competition set in 

 between the French and German makes, which was further aceen- 

 tuated by additions, in Fiance. Germany and Switzerland, to the 

 number of linns making vanillin. The result has been that the price 

 of this product, which was £'.» per lb. in 1890, has steadily fallen 

 until in November last it was quoted at £ 1 1 1 per lb. It is probable 

 that all the vanillin so far placed on the market has been made from 

 eugenol. and its price has therefore been governed by that of oil of 

 cloves as the raw product. In 1901 however, a patent (No. 310,988) 

 was taken out in France by Vigne, in which an electrolytic method 

 for the preparation of vanillin from sugar was described. If the 



