Vol. III. No. 68. 



THE AGEICULTUKAL NEWS. 



371 



I 



cfinnot jmt into bags, theroforo tlie (jiiestion that I have 

 alrwuly often dealt with remains still the same — to wliat point 

 of degree of extraction can we go and obtain tlie sugiu' that 

 we extract ! This is, and must always be, the technical 

 business-man's first consideration. Total e.\traction is 

 jpossible, but it is nonsense in practice. Beyond a given 

 degree, governed by the quality of the cane, but also with 

 best of cane, extraction does not only not increase the yield 

 of marketable sugar, but it can actually lessen it : increase of 

 molasses, and usually of higher sugar content, is the result. 

 A word or two indicating what it actually means, on 

 the one hand, to gain a [ler cent, in extraction, and what, on 

 the other hand, it means to increase the molasses per ton of 

 .sugar, and therewith increase the sugar content of the 

 molasses which usually follows as a result of bringing out 

 more of the impurities that get in the way of crystallization. 

 If we take as a basis a crop of 10,000 short tons or 

 20,000,000 If), of sugar, then each per cent, is equal to 

 100 tons. AVe therefore estimate that for each per cent, of 

 extraction over, say, 91 per cent, (high-grade cane) 100 tons 

 of sugar is brought into process of manufacture. That is, 

 tlie extra one per cent, gives the opportunitj' of making 

 100 tons more sugar on the basis of the 10,000-ton crop. 

 ()n the other hand, 2.5 gallons (American) per ton of sugar 

 means a very low average, 2.50,000 gallons or 3,000,000 t). 

 upon a 10,000-ton croj). One gallon of molasses is therefipre 

 equal to 120,000 Itj., and if the molasses are composed of one- 

 third cane sugar, and the average is higher than this by 

 double polarization, then 1 gallon of molasses upon 

 a 10,000-ton crop is equal to 20 tons of sugar. An increase, 

 then, of 5 gallons of molasses jier ton of sugar by heavy 

 maceration would be equal to 100 tons of sugar upon the 

 10,000-ton crop, or one per cent, of extra extraction. 



Again, one per cent, increase of cane sugar left in the 

 molasses, at the rate of 25 gallons per ton of sugar, is equal 

 to 15 tons of sugar (or 18 tons of the molasses is increased 

 to 30 gallons per ton of sugar) upon a 10,000-ton crop. In 

 brief, if in the attempt to raise the extraction from 91 \)ev 

 cent, to 95 per cent, by excessive use of water, or b}' 

 returning third-roller dilute juices, the molasses should be 

 increased 3 gallons j'er ton of sugar, and the sugar 

 content of the molasses raised by 2 per cent., then the extra 

 100 tons of sugar brought into the manufacture by the one 

 per cent, greater extraction is valueless, for it is never 

 obtaired, and the fuel, labour, and time spent are thrown 

 away. If chemists, and the technical controllers of sugar 

 houses, will keep steadilj- in view the extra sugar obtained, 

 instead of mere increase of extraction, they will be working 

 towards something actual ; and if to this the}" will add the 

 account of cost of obtaining the extra sugar under varying 

 prices of fuel, then they will be able to render a strictly 

 business statement of their work. Of course, I am not deal- 

 ing with the gross difference between the work done by 

 old-time and modern-time high-power mills, but rather witli 

 extractions of the best mills, upon high-grade cane, with 

 large volumes of water, and the actual economic results. 



In the matter of \arying qualities of cane, I have reason 

 to believe that, with the grades of cane containing 10 per 

 cent, to 12 per cent, of sugar, any extraction over 88 per 

 cent, or 90 per cent, only goes to make molasses, and with 

 the best cjuality of cane, say, a sugar quality of 16 per cent, 

 to 18 per cent., we are j'et without evidence that any 

 extraction above 95 per cent, has resulted in any gain of 

 marketable sugar. On the other hand, there is ample 

 evidence that excessive maceration and a forced extraction 

 liave actually led to a loss of obtainable sugar. This has been 

 j*hown by me in earlier publications. 



RATS CLEARED PROM AN EGYPTIAN 

 PUBLIC GARDEN BY LIZARDS. 



The following note on lizards clearing field rats 

 from the Delta Barrage Public Gardens, Egypt, has 

 been forwarded by Mr. Walter Draper: — 



The Government Gardens, Delta Ranage, near Cairo, 

 have for some time suffered consideralily from damage caused 

 l)y the Egyptian field rat, which congregates in large 

 numbers on raised lands and canal l)anks throughout the 

 country, particularly during high Nile. This species, which 

 is eaten by negros, has not the nocturnal habit of the 

 hou.se rat, from which it differs in having a smaller head, 

 less [lointed nose, and its hair, which is a dark colour tip[ied 

 with brown, is coarse and somewhat erect. Its favourite 

 feeding time is late afternoon, when it attacks the bark of 

 tender trees, young bamboo shoots, stems of ivy, etc. It 

 causes considerable damage to rockeries and stone revetments 

 by the quantity- of earth it removes when burrowing. It 

 is easily trapped, but large numbers when established make 

 complete eradication difficult. 



Four or five years ago some twenty lizards {Againa 

 stflUs) of a dark, rough-backed, tree-climbing .species were 

 introduced by the writer into the gardens from Alexandria. 



This rei)tile, which is about 10 inches long, runs with 

 great rapidity, and is of a somewhat striking appearance, like 

 a small crocodile. The fact that the gardens are protected 

 on three sides by the Nile has probably been of some 

 assistance in locating these lizards in the gardens, where 

 the}' have now increased considerably. Their favourite 

 haunts are holes in rockeries made by rats, and also in 

 decayed piortions of trees. 



A few years ago the rats began to disappear, as the lizards 

 increased, until a rat in the gardens is now \ery rarely 

 seen. The writer was informed by a gardener that he had 

 seen a lizard with a young rat or mouse in its mouth : but 

 unfortunately, I am unable to vouch for the accuracy of this 

 statement. Sufficient, however, is that the damage caused by 

 field rats has now ceased, and the large lizards form by no 

 means an unpleasant feature in the animal life of the Public 

 Gardens. 



Chameleons have been introduced from the deseit, but 

 so far without success. 



PARA RUBBER. 



In the A nmial Report on the Federated Malay 

 States for 1903 the Resident-General says : — 



I am not in a position to give the figures of acreage under 

 Para rubber cultivation, but it is extending rapidly, and the 

 most sanguine hopes are entertained — and reasonably 

 entertained — as to its prospects of success in these States. 

 Export in cjuantity has not yet commenced, but adequate 

 authorities have reported that our samples are equal, if not 

 superior, in quality to Ceylon rubber, which has hitherto 

 headed the market, while experienced visitors from that 

 colony and from Java pronounce the growth of the trees to 

 be magnificent. Sources of natural supply of rubber appear 

 to be shrinking, while, at the same time, new uses for the 

 article are being found, and its consumption is increasing. 

 It may reasonably be expected that, as with cinchona, 

 cultivated Para will beat the wild product. The prospect for 

 our Para rubber planters appears to be most favourable ; 

 additional areas are being brought under cultivation, 

 companies and syndicates are being formed, and it is ho[ied 

 that over-capitalization will be avoided. 



