Vol. XVIII, No. 43S. 



THE AGRICULTURAL XEWS 



cent... \vhich, &s Mr. Kob.<iut sivs?, would amply piy 

 the labour involved in staking. 



In connexion with this e.vperimGiit;, Mr. Robson 

 iiOt.es that, from the tiaie of planting the weather was 

 drv until the end of Avi^ust. when ample rains began 

 and continued for the next two months. This indicates, 

 he considers, seeing that the resulting crop was .?cuis- 

 factory in amount, that the months of September .and 

 October are the critical perioil f'«r the development of 

 the yam. 



Toxic Principles of Cofiee. 



It has long been recognized that coffee possesses 

 properties which cause inconvenience to some individ- 

 uals, though others are able to use the beverage without 

 any such inconvenience. For a long time it wa? siig- 

 o-ested that it was the active alkaloid, caffeine, that was 

 the cause of the symptoms complained of, but investi- 

 gation has shown that these symptoms do not accord 

 with those produced by caffeine, and other explanations 

 are sought. 



In a paper published in the Tidn^action^ of thf- 

 A'(ivs<is Acwfi'iiiy of ydey^c", Professor L. K. Sayre 

 review.s the (|uestion, and supports the idea that the 

 toxic principle complained of is geneiated in the pro- 

 cess of roasting the coffee berry. It i-'^ conjectured th;it 

 certain pyridine derivates may be built up during the 

 process of roasting, and that these may constitute the 

 toxic agents. 



As the result of these investigations, the hope is 

 expressed that methods of heating or roasting coffee 

 may be devised, whereby the formation of these objec- 

 tionable bodies may be prevented, so that no coffee 

 drinker may be exposed to the unpleasant effects which 

 some experience. 



I'rofessor Sayre says that while coffee contains 

 these toxic principles, it does ncn- necessarily indicate, as 

 some might suppose, that coffee is poisonous. Although 

 some people are so constituted that they cannot use 

 coffee, thousands of others use it without harmful effects, 

 and even seem to receive benefit from its use. There- 

 fore we should not condemn coffee simply because 

 the toxic principle, which has always existed, has 

 been identified more certainly. He adds, it might 

 be said that it is very piobable that this toxin can be 

 removed. In fact, a process is now in use by which at 

 least part of this toxic principle is expelled, and by 

 further experimentation the process can he further 

 improved. 



The Effect of Liming on Crop Yields. 



A series of experiments in cylinders on the effect 

 of liming on crop yields in conjunction with fertilizers 

 has been undertaken at the New Jersey Agricultural 

 Experiment Station for twenty years. The results are 

 recoided in a paper by J. (.}. Lipman and A W. Blair, 

 published in So-iL t?r,l.encf, August 191S. 



Four series of cylinders were annually treated 

 with applications of acid phosphate and muriate of 

 potash eijiiivalent to <)4(> and '-'dO 1h. per acre, respec- 

 tively. In addition, nitrogenous fertilizers have been 

 applud annually as folhnvs : to the first series, nitrate 



of soda at the rati- of 160 th. per acre; to the second, 

 nitrate of soda at the rate of 320 ft. per acre: to the 

 third, ammoniuia .'^nlphaie equivalent to 320 tb. of 

 nitrate of soda p^r acre: and to the fourth, dried blood 

 equivalent to 320 ft, of nitrate of soda per acre. All 

 the cylinders received a generous application of ground 

 limestone when the ixperimeiits were started. Each 

 series was ia triplicate, and afcer the first period of ten 

 years no further lime was given to lot A, while lots 

 B and C continued to receive a generous application 

 once in the five-crop lotation, and in addition, lot C" wa-s^ 

 put under a leguminuus crop as a 'green manure twice 

 in each rotation. ^ 



The results at the end of twenty years show thab 

 where commercial fertilizer alone is used as a source ot" 

 plant food, in amounts corresponding to those employed 

 in the experiments, there would be a marked accu- 

 mulation of soil acidit}-, and a very marked improve- 

 ment in plant growth after the application of adequate 

 quantities of lime. Lot A gave very inferior yields to the 

 others, while lot C was distinctly superior. The con- 

 tinued use therefore of acid phosphate, nuinate of pot- 

 ash, nitrate of soda, sulphate of ammonia, and dried blood 

 is bound to lead, sooner or later, to an unsatisfactory 

 soil reaction, and to the need of generous applicitions- 

 of lime. 



The writers lay stress on the importance ot 

 systematic and adequate liming of land, the production- 

 of which it is sought to bring up to constantly higher 

 levels, by the generous use of commercial fertilizers. 



Emphasis is also laid on the importance of intro- 

 ducing leguminous crops in the rotation at frequent! 

 intervals for the purpose of increasing the supply of 

 available nitrogen, and also of maintaminof a soihI 

 suppl}- of organic matter. 



Vitality of Acacia Seeds. 



Some seeds possess an extraordinary power of" 

 keeping their vitalit\ under the most ad\erse condi- 

 tions. This is notably the case with seeds which 

 possess a very hard shell or testa .Studies on the 

 vitality of the seed.-^ of Acacia iarncsiana. well known 

 in the West Indies, the pods of which are of some 

 value in tanning, have been undertaken by R. H. Cam- 

 bage in New South Wales. A note on the results- 

 appears in the Erpcriiucnt ^Station Record, November 

 15. 191.S. which shows that the seeds of this plant seem 

 to be able to stand any kind of treatment, and yet be 

 able to germinate. 



A seed of A. farnesiana was soaked for 40.5 days- 

 in sea-water, and then planted. After five weeks it- 

 was examined, placed in boiling water, and replanted. 

 It was re-examined after nine weeks, again placed in 

 boiling water, and once more planted, and after five 

 weeks it finally sprouted. Another seed sprouted after 

 having been in the soil twenty-three months. It is 

 stated that the softening of the hard coat of the 

 seeds, requisite to sprouting, is often accomplished in 

 the natural surroundirgs of the plant by bush fires- 

 < Itherwise the seeds may remain dormant in the soil 

 for years. Thev may also be transported by water fur 

 thousands of miles and then gorniinate. 



