Vol. XII. Xo. 279. 



THE AGRICULTURAL NEWS. 



and critical survey of the cheiriistry of cacao is the 

 brevity of the section dealing with its cuitivatioD. 

 Nature points out the omission of certain important 

 facts which may not be commonly known, even in the 

 AVest Indies. For instance, much of the Gold Coast 

 cacao is marketed in an unfermented condition: and 

 the fact that some manufacturers in the Ignited 

 Kingdom prefer unwashed cacao, alleging that it is of 

 better flavour than the washed article, seems particularly 

 noteworthy, as also does the suggestion that the 

 practice of 'claying' easily degenerates into nn re 

 'weighting'. 



The above volume is, of course, designed for the 

 use of manufacturers and chemists; the secund book, 

 by W. H. .lohnson, meets the requirements of the 

 planter, rather than those of the i Manufacturer. Owing 

 to Mr. Johnson's having acquired experience in the 

 West Indies, the Gold Coast and Ceylon, his 

 information is devoid of bias in favour of the practice 

 of some particular area — a statement which cannot be 

 said to a])ply to most text-books on cacao. Such 

 .matters as the selection of a site and the formation of 

 a plantation are dealt with in such a way as to affoid 

 a useful guide in future planting. The preparation of 

 cacao for the market, and especially such fundamental 

 matters as fermentation, washing and 'claying' are very 

 well discussed, and the work as a whole should prove 

 particularly useful in places where cacao is the chief 

 article of export. 



This volume is the second in the series of Imperial 

 Institute Handbooks, prepared with special reference 

 1;<j the requirements of British West Africa. 



The first of the.se books is published at Ins. net, by 

 J. and A. Churchill: the price of the second is .")«. net. 



Plant Respiration and Sudden Changes of 



Temperature. 



In the Bulletin of tlie Bureau of Agriiulturai 

 Jntelligence and of Plant Diseases, No. 9. 1912, an 

 account is given of research woi'k on the above subject 

 recently conducted in France. It appears that the 

 technique adopted in former experiments on the 

 -subject was open to criticism, the lesults of the ditfer- 

 <ent sets of experiments not being strictly compar- 

 able. In the research under review, the investigator took 

 seedlings of kidney bean {Phaseolus vuUjaris) deprived 

 of the cotyledons and grown in distilled water, shoots of 

 the broad bean ( Vicia Faha) and young leaves of rye 

 iSi/iale cereale) which had {jreviously been placed in 

 -I 10-percent, saccharine solution. In each experiment 

 he took only one group, in order to avoid the individual 

 differences always presented even by groups similar to 

 *ach other. The study of respiration was made by the 

 juethod of confined air, subjecting the graduated test 

 vessels in which the respiration took place successively 

 for a given time ( usually very short ) to the different tem- 

 peratures provided for in the experiment. At the end of 

 each experimental phase the carbon dioxide in a remov- 

 ed sample of air was measured. The results showed that 



sudden variations in temperature do not gi\'e rise to p.ny 

 stimulus to respiration, and that between the respirat- 

 ing activity corresponding to a given temperature and 

 and that for a different temperature, the transition 

 takes place gradually and compriGcs all the intermedi- 

 ate respiratory activities between those of the extreme 

 temperatures. 



Useful Fibre from Maize Stalks. 



A typical example of an investigation in which 

 secondary results proved to be of primary importance 

 is referred to in the Experiment Station Record for 

 September 1912. 



The object of the experiment was, in the first 

 instance, to find out whether removing cobs from the 

 corn stalk in the milk stage, instead of allowing them 

 to mature, increased the sugar content of the stalk, as 

 is supposed in the Stewart method for obtaining sugar 

 from maize stalks. Negative results were obtained; 

 but in the course of the experiments it was observed 

 that when cobs were removed there was very little 

 deposition of the hard siliceous matter which forms the 

 outer coating of the maize stalk and thus prevents the 

 use of the best fibrous matter when the cobs are 

 allowed to ripen. 



Consequently the removal of cobs renders the 

 whole stalk resolvable into pulp and cellulose of the 

 finest quality for paper and for all the the higher uses 

 for which cotton cellulose is now employed. 



The Importance of Naphthalene in Creasote. 



A somewhat remarkable discovery is referred to 

 in the Experiment Station Record, for September 

 1912, in connexion with the quantity and quality of 

 creas<.ite found in two treated piles after long service. 



It appears that about thirty years ago two wooden 

 piles — records of the method of treatment are not 

 available — were employed for some purpose in the 

 ti -redo- infected waters of the Gulf of Mexico. A recent 

 examination has shown that one of the piles is per- 

 fectly sound, whereas the other has been attacked, 

 particularly at the water line. 



Chemical analyses have demonstrated that the crea- 

 sote in the perfectly preserN ed pile originally contained 

 at least 40 per cent, of naphthalene fractions, a large 

 portion <if which have remained in the wood. The. 

 creasote in the less perfectly preserved pile contained 

 little or no naphthalene. 



Since naphthalene is a solid hydrocarbon which, 

 according to recent work by J. M. Weiss, possesses a low 

 antiseptic value, it would seem probable that the physi- 

 cal properties of this compound were to some extent 

 responsible for the differences in the condition of the 

 creasoted piles. Paraffin is another solid hydrocarbon, 

 and although it possesses no antiseptic properties at 

 all, it is able to prevent the decomposition of healthy 

 tissue embeddetl in it. 



