Vol. XI. No. 267. 



THE AGRICULTURAL NEWS. 



227 



experimental difficulties of such investigations are 

 very great: the growth of bacteria in the water cultures, 

 and of bacteria and algae in sand cultures, and the 

 changes that take place normally in soils, all confuse the 

 issue, so that what can be said actually is: 'Our conclu- 

 sion, therefore, is that there is no unexceptionable 

 evidence of any toxin excretion by plant roots.' 



The article by Russell proceeds to deal with the 

 circumstance that agricultural literature contain* 

 many statements to the effect that crops may be pois- 

 oned through succeeding other crops, and in passing 

 refers to Daubeny's work, of many years ago, which led 

 to conclusions other than that expressed in de Can- 

 dolle's hypothesis that plants excrete toxins; he also 

 mentions the fact that Pickerings investigations of the 

 harmful effect of grass on fruit trees have not shown 

 that this is due to any poisonous excretion. Attention 

 is then given to several results that have been obtained 

 at Rothamsted, which are inexplicable at present, and 

 do not yield to any form of explanation founded on the 

 theories of Whitney. Reference is made here to the 

 original article for a very interesting treatment of 

 these matters. 



The work of those who are engaged in pulling 

 forward the theory of toxins in regard to soil fertility 

 has suffered, as Rus.sell states: 'from leaving out of 

 consideration all biological changes going on in the 

 soil.' We can agree nevertheless with that writer in 

 saying: 'The investigations have, however, served 

 a very useful purpose in stimulating eni[uiry and they 

 have brought home the fact that the relationships 

 between soils and plants are complex,' and again: 

 'Whether farther work support their hypothesis or not, 

 Whitney, Cameron, Schreiner and their colleagues have 

 made agricultural chemists re-examine their ideas on 

 the soil, and such a reconsider.itinn must in the end 

 advance the subject, however troublesome or sui)er- 

 fluous it may at the time appear.' In the meantime, 

 it may be added, experimental work on the more prac- 

 tical scale will continue to be done, and those who have 

 its performance in their hands will await eagerly the 

 further guidance that is expected from investigators 

 who pursue their researches in a more detailed manner. 



A copy of a publication entitled The Cult of the Coco- 

 nut, that .should be particularly useful from a commercial 

 point of view has been received recently. This deals with 

 the past and future development of the coconut, copra and 

 palm oil industries; it also contains a section dealing with 

 the oil palm of West Africa (Elaiis guimensis). The 

 work is well illustrated, and may be obtained, price 2s. 6d. 

 net, from Messrs. Curtis, Gardner i^- Co., Ltd., Spencer House, 

 South Place, Finsbury, London, E.G. 



SUGAR MANUFACTURE IN JAVA, 

 1910. 



There has been received recently a set of tables 

 prepared by J. J. Hazewunkel, setting forth facts 

 connected with sugar manufacture in Java, under the 

 system of matual control whereby the figures relating 

 to the working of the different factories are furnished 

 for publication and comparison. These tables have 

 reference to the year 1910, and the average results 

 obtained in regard to several of the more important 

 items are presented below for the use of readers of 

 the Agricultural Ncirs: — 



Sucrose, per cent, in cane 

 Purity of mixed juice 

 Sugar in bags and baskets* 

 Sugar in black stroopf, A centr. 09 \ 

 Bbags 014/ 

 Sucrose obtained in sugar and black stroop") 



per 100 cane J 



Available sucrose { Hazewinkel's formula) 

 Maceration water in 100 parts normal juice 

 Moisture in megass 

 Normal juice per 100 fibre* 

 .Juice extricted, on 100 parts of juice in cane 

 Fibre per 100 cane 

 Purity, final molasses 

 Sucrose per 100 megass 

 Juice of first mill, Brix 



„ „ „ „ sucrose 



.. ,. ,. ,. purity 



,, ,, final mill, sucrose 



., ,. ,, ., purity 

 Mixed juice, Brix 



,, ,, sucrose 

 f flucose ratio in mixed juice 



12-54 



84 67 

 1018 



02.3 



1026 



10-3.5 



14.3 



46-72 



55-2 



91-2 



12 27 



33-42 



4:52 

 17-89 

 15-55 

 86-49 



6 08 

 79-76 

 15-73 

 13-32 



7-26 



The Manna Plant. — A recent issue of the P/tarma- 

 i-eutical Journal and Pharmacist gives interesting particulars 

 of the manna of the Bible. The plant, Lecanora esculenta, 

 is found over a region covering south-west Asia, extending 

 to south-east Europe and to north-west Africa. It appears 

 on small stones, preferably small chalky pebbles, first as thick, 

 wrinkled warty crusts, greyish-yellow on the outside and 

 having a white mealy fracture. Later the flakes become 

 cracked, detach themselves from the stones, and roll up into 

 bullet-shaped or warty masses of about the size of a Hazel 

 nut. When the rain comes the manna quickly absorbs 

 moisture, and bursts into large flakes which have a mealy 

 interior. When we consider that the dry manna, plants are 

 carried considerable distances by the wind, and are often 

 blown together in considerable quantities, this rapid change 

 from hard, dry, almost stone like substances into a fliky 

 food may well have induced the belief of the Israelites 

 that the manna fell from heaven. In Persia manna is used 

 as a food, and is also given under the name of 'Chirzade' to 

 feeble and ill-nourished mothers as a lactogogue in daily 

 doses of 150 to 200 grammes. The food value of manna lies 

 in its 20 to 25 per cent, of lichenin. (The Gardeners' Chron- 

 icle, June 1, 1912.) 



■* Sugar already obtained. 



t Sugar to be obtained. 



t Corrected for variation in sucrose and fibre in cane. 



