Vol. X. No. 251. 



THE AGRICULTURAL NEWS. 



The Bacterial Deterioration of Sugars. 



A study of the bacterial deterioration of sugars 

 receives attention in the Louisiana Stations Bidletin, 

 No. 2.5, where the opinion is given that it is caused by the 

 potato group of bacilli. A matter of interest and prac- 

 tical importance is that the spores of the kinds that were 

 examined were found to be capable of resisting the 

 effects of high temperatures. The changes in the 

 sugar are stated to be due to an extracellular, gum- 

 forming enzyme which has been called Levanase. 



Attention is drawn to the fact that the presence 

 of the gum in sugars introduces an error in sucrose 

 determinations, in both the single polarization and the 

 Clerget methods. The amount of the error in the 

 former is a decrease of 0(i Ventzke for every 1 percent. 

 of the gum present; in the Clerget method the same 

 amount of gum gives an increase of 0'67' Ventzke. 



Further Work with Sleeping Sickness in Cen- 

 tral Africa. 



It is stated in Nature for October 19, 1911, that, 

 according to Reuters agency, a further commission is 

 being despatched to Central Africa in connexion with 

 sleeping sickness. The Commission will be in charge 

 ol Colonel Sir David Bruce, and will include Professor 

 Newstead of the Liverpool School of Tropical Medicine. 

 Operations will be confined to Nya.saland, where more 

 than forty cases of sleeping sickness have occurred since 

 1909, and it is expected that the Commission will be 

 absent for three years. Sir David Bruce left Marseilles 

 on November 10. It is being sent out by the Govern- 

 ment under the auspices of the Royal Society, and one 

 of its principal objects is to ascertain if there is any 

 connexion between the presence of big game and the 

 existence of the fly that is supposed to be responsible 

 for sleeping sickness in Nyasaland. 



Trade and Agriculture of the Gold Coast, 1910. 



In Colonial Reports — Annual, No. 688, it is stated 

 that the gross value of exports from the Gold Coast in 

 1910 amounted to £2,697,706, as against £2,65.5,-573 

 in 1909; this is an increase of £42,133, exclusive of 

 specie, and is siid to be due to the expansion of agri- 

 cultural industries and the conseiiuent larger shipments 

 of economic products. 



The quantities and values of the chief agricultural 

 products exported during the year were as follows: 

 cacao 50,692,949 lb., value £866,571; kola nuts 

 .5,156,500 lb., value £77,716; palm kernels 14,182 tons, 

 value £185,058; palm oil 2,044,868, gallons, value 

 £161,388; rubber 3,223,265 lb., value £358,876; lumber 

 14,938,749 feet, value £148,122. 



The chief increases over the exports of the 

 previous year took place in regard to the first and last 

 four of these products. The principal decreases in the 

 value of exports are with respect to: gold, gold dust 

 and concentrates; specie; and kola nuts. 



Tapping Experiments with Castiu^ 



An account of the results obtained froni 

 two Castilloa trees at the Botanic Gardens, Grena,. 

 has been forwarded by Mr. G. G. Auchinleck, B.Sc, 

 the Superintendent of Agriculture. An examination 

 in the laboratory, of the rubber obtained, gave the 

 following percentages: loss on washing, 2'01; caout- 

 chouc, 8005; resin, extracted by acetone, 1665; ash, on 

 crude rubber, 141. 



Mr. Auchinleck states that the latex was obtained 

 by lightly scoring channels with a Golledge knife, and 

 puncturing the floor of the channels with a chisel; good 

 results were not obtained from the use of the knife 

 alone, as it tended to close the latex vessels. One side 

 of each tree received a single perpendicular cut 2 to 3 

 feet long, with four or five subsidiary channels about 

 18 inches long and 8 inches apart. Coagulation was 

 effected with 2 or 3 oz. of acetic acid, in wooden 

 vessels. The total yield of dry rubber was somewhat 

 small, for the trees were at least nine or ten years old; 

 it amounted to 70'65 grams (21 oz. ). An explanation 

 of the last circumstance is suggested in the fact of the 

 dryness of the soil of the Gardens, and that tapping 

 was only done on one side of each tree. The sample of 

 rubber obtained became tacky in four months. 



The results of the experiment are of special 

 interest, as they are the first information of the kind 

 that is available from Grenada, 



The Formation of Prussic Acid During Germin- 

 ation. 



Past investigations have shown that some seeds, 

 such as sweet almonds and those of Mesjiilus japonica, 

 form large quantities of prussic (hydrocyanic) acid when 

 they begin to germinate. In reviewing recent experi- 

 ments in connexion with the subject, Nature for Novem- 

 ber 2, 1911, draws attention to the work of Guignard 

 with the Lima bean (Pkaseolus lunatus) which demon- 

 strated that decomposition of prussic acid takes place, 

 on the other hand, when the seeds begin to sprout, 

 paiticularly in the case of plants kept in the dark. 



The work which it is the special object of the 

 note in Nature to review was conducted with the seed 

 of Ciuinea corn, which does not contain appreciable 

 traces of prussic acid, and of a variety of linseed in 

 which it is present to a considerable extent. With the 

 Guinea corn seed, prussic acid was formed during 

 germination, until a certain stage was reached, when 

 it appeared to be progressively destroyed; in the case of 

 linseed, there was a continuous increase in the projwr- 

 tion of the compound present, without any observable 

 decomposition. The production of the prussic acid 

 was always greater in green plants than in those kept 

 in the dark; but if the latter were watered during 

 growth with a 2 per cent, solution of glucose, the 

 proportion of prussic acid became equal to that in the 

 green plants. This shows that the formation of the 

 prussic acid is greatly influenced by the amount of 

 carbohydrates in the seeds. Further investigations 

 are to be made, in order to determine the source of th« 

 nitrogen employed in the formation of the acid. 



