ToL. VII. Xo. 161. 



THE AGKICULTURAL NEWS 



■205 



Kr^ 



THE I'RIXCJrLES OF AdltlV f LTf RE. By 

 Petei- M. (If AVeever, Master at the Govenimfut Imlustrial 

 School, British Guiana. Pnblhlicd liy th<j 'Aiyaxii' ('uni^ii-nii/ 

 Ltd., Geoiyatoii'n. 



Now that increasing attention is being given to teaching 

 -agricultural science in the elementary schools of the West 

 Indies and British Guiana, there naturally arises a demand 

 on the part of the teachers for a handbook indicating the 

 lines on which the subject should be taught. The above 

 book, it is stated by the author in the preface, was written 

 with the object of meeting this need so far as the elementary 

 school teachers of British Guiana are concerned. It should 

 certainly prove useful for the purpose, since it contains, 

 within the compass of 87 pages, a large amount of elementary 

 information on soils, their formation, and the methods of treat- 

 ment (draining, lining, manuring, etc.) which improve their 

 agricultural value, plant life and growth, the pniximate 

 constituents of plants and animals, etc. The latter j)art of the 

 book deals with practical demonstration work before the class, 

 and contains notes on a number of experiments which illas- 

 trate the princi[iles conveyed in the lessons. 



LE CACAOYER AU CONGO FRAXCAIS. By 

 C. Chalot and M. Lnc. PnhJixked Iji/ Aw/uxtiii Cladhniul, 17 

 Rnc Jacoh^ I'an'x. 



The output of cacao from the French Congo has shown 

 a continuous increase during the past ten years. In 1 S9f) the 

 exports were -5,14.3 kilograms [1 kilogram = L''2D5.]; three years 

 later the shipments had advanced to "23, '249 kilos., and in 1902 

 they reached58,398 kilns., uiulc in 1 904 the total cacao exports 

 were 91,092 kilos. 



On account of the increasing importance of the industry, 

 and in order to give useful and reliable information as to 

 the best methods of culti vatioi i, preparation of the |)roduce, etc., 

 to those engaged in cacao culture, the abo\e Ijook of sixty j)ages 

 has been written by two officials connected \\ith the Depart- 

 ment of Agriculture of French Congo. 



The book gives an account of the different \arieties of 

 cacao, with their comparative values, and discusses the most 

 suitable conditions of soil and climate, methods of raising 

 and planting young seedlings, the question of sheltei-, both 

 from sun and wind, and the later treatment of the plantation, 

 jjruning, raising young trees, etc. Finallj', directions are 

 given as to harvesting, fermenting, drying, and shipping the 

 ■crop. The book is illustrated with )-e|iroductions of photo- 

 graphs and with diagrams. 



THE VASE FOR THE GOAT. By ' Home Counties' 

 Published by CJeorge Unntledge .t Sons, Limited, London. 

 Price 3.S. 6'/. 



This book, it is stated in the introduction, has been 

 written in the hope of removing some of the ignorance and 

 prejudice that exist in the minds of many in regard to the 

 .goat, and with the object of spreading a better knowledge of 



the valuable milk-yielding properties of these useful and 

 cheaply-kept animals. Interesting data is given as to the 

 amount of milk yielded by goats, while it is pointed out that 

 this milk is not only much richer, but also more digestil>Ie 

 than cow's milk, and therefore more suitable as a food for 

 children. The management and feeding of goats, and the 

 relative nulking value of the different breeds are also discuss- 

 ed in the book. A lengthy appendix contains the answers, 

 furnished by experienced goat keepers, to twenty-four 

 questions on the subject of goat keeping, addres.sed to them 

 b}- the author. In reply to the query as to the best breeds of 

 goat for milking purposes, the Toggeuburg and the Anglo- 

 Xubian are moitioned in practically all eases. Most goat 

 keepers state their opinion that a yield of about 2 (juarts of 

 milk per day should be expected from a nanny ^vith lier 

 second kid, and this amount should be kept up for several 

 months. 



The book is abundantly illustrated with photographs of 

 representative animals of the various breeds. 



THE FERMENTATION OF CACAO. 



Considerable ditf:erence of opinion still exists as to 

 the process involved in the fermentation of cacao, as 

 well as the purpose and necessity of the operation. It 

 is now generally believed, however, that yeast cells play 

 an important part in bringing about the fermentation. 

 Most probably, too, bacteria and enzymes also assist in 

 the process. This subject is discussed in detail in the 

 course of a lengthy article that appears in the Annual 

 Report (1907) of the Porto Rico Agricultural Experi- 

 ment Station. The following summary embodies the 

 conclusions arrived at by the author (Mr. Oscar Loew, 

 Physiologist at the Station) on the subject: — 



The fermentation process itself is due in the first place 

 to the presence and action of j-east cells, which multiply 

 rapidly in the saccharine juice oozing from the pulped cacao, 

 and produce alcohol and carbon dioxide. Bacteria, whio-li 

 develop rapidly after a certain time, also participate, and by 

 their action, the alcohol formed by the yeast is converted by 

 oxidation either wholly or partially, into acetic acid. These 

 processes cause a rise of temperature and the death of the 

 cells of seed and slime tissue, whereupon the juice of the 

 slime tissue, more or less altered, collects at the bottom of 

 the recei.itacles, together with the acetic acid produced. 



The chief object of the fermentation is to shrink the 

 slime tissue or pulp attached to the testa of the seed, allowing 

 the remnants either to be washed away as is done in Ceylon, 

 or dried upon the seed, forming an irregular brown film upon 

 the testa. As the result of diminishing the amount of slime 

 tissue present, the drying of the seed is much facilitated. The 

 loosening of the adhesion between the seed and the testa, and 

 the hardening of the testa are claimed as further effects of 

 fermentation. 



The fermentation has also an indirect influence on 

 changes going on within the seed, inasmuch as by the 

 temperatures produced (104' F. to 122" V.) tlte cells of the 

 seeds are killed, thus liberating the oxidi/.iug enzymes, which 

 cause the formation of the brown colour, by oxidation of the 

 tannin of the seed. This brown colocuution is increase) 1 

 during the drying process, and finally by the roasting. 



The taste of the raw cacao bean is not only altered by 

 the partial oxidation of tannin during the fermentation or 

 sun-drying of the seed, but also by products of roasting. 

 The action of oxidizing enzymes, as well as the final roastinj; 

 process, play a part in the development of the aroma. 



