Vol. X. No. 246. 



THE AGRICULTURAL NEWS. 



313 



the expenditure of very large sums of money has been 

 planted with trees that can only yield a low grade 

 rubber. 



It is evident that, since thirty-five years have 

 elapsed since these seeds were collected, there has been 

 sufficient time for the better trees in the district to 

 have been destroyed by the careless methods of tapping 

 that were employed up to a few years ago; while the 

 inferior trees that are lefo are only now receiving atten- 

 tion for collecting. There is the farther matter of the 

 assertion by Mr. Wickham that the seeds were obtained 

 by him from trees yielding rubber of the best quality. 



The circumstances were sufficiently important for 

 it to be decided that tests should be made, at the Exhi- 

 bition, of rubber from the two sources: and to state the 

 re.sults shortly, it was found that a sample of plantation 

 rubber sent as an exhibit from the Botanic Gardens, 

 Singapore, and coagulated on a revolving stick by 

 means of smoke, gave almost identical results, on being 

 suitably tested, as those obtained fioui a sample of fine 

 Para. The differences, as a matter of fact, were so slight 

 that they would probably disapjiear, for all practical 

 purposes, under a large number of tests. The statement 

 is made that it may be concluded, 'as the result of these 

 most interesting experiments, that when Malayan 

 plantation rubber is prepared in the same way as 

 Brazilian rubber, the two substances are indistin- 

 guishable in quality, and that there i.s a .strong prob- 

 ability that they are the product of one and the same 

 species of Hevea.' 



In presenting the results, a warning is given 

 against concluding that the only way to coagulate Para 

 rubber, in order to obtain the l>est product, is the 

 employment of the method of smoking, and attention 

 is drawn to the fact that a sample of such rubber, 

 obtained with the aid of acetic acid, gave even better 

 tests than those which have just been mentioned. 



The Properties of Nitrate of Lime. 



The Journal of the lioyal Horticulbiral Society 

 for May 1911 gives, as one of the contributions from 

 the Wisley Laboratory, an article on calcium cyana- 

 mide and nitrate of lime; part of this has reference to 

 the properties of the latter manure. Attention is drawn 

 to the fact that commercial nitrate of lime is a pale 

 brownish compound, free from smell, arid at first finely 

 granular. The amount of calcium nitrate present is 75 

 to 77 per cent.; the rest is water and a very small 

 amount of other substances. As is well known, nitrate 

 of lime is very soluble in water: not only this, but it 

 possesses in a marked d^^gree the property of absorb- 

 ing moisture from the air. 



In connexion with the last mentioned property, 

 an experiment was devised for the purpose, of com- 

 paring it in this respect, with calcium cyana- 

 mide and nitrate of soda. For the purpose, weighed 

 quantities of each substance were jilaced in small open 

 dishes standing over water, under bell jars — an arrange- 

 ntent which gave the best chance for water to be absorb- 

 ed. The dishes and their contents were again weighed 



after forty-eight and 120 hours of exposure to the mois- 

 ture-laden atmosphere. At the end of the first period, 

 100 parts by weight of the calcium cyanamide, the 

 nikrate of soda and the nitrate of lime had increased 

 respectively to 1027, 105-8 and 115'6; while at the end 

 of 120 hours the similar figures were 1587, 226 9 and 

 247.2. 



It is thus seen that nitrate of lime absorbs water 

 from the air very readily indeed, the effect being to 

 produce a sticky mass in the place of a granular sub- 

 stance. The possession of this property makes it diffi- 

 cult to apply the manure to the soil unless it is used 

 immediately after the packages are ojiened. The diffi- 

 culty appears to have been partly met in some instan- 

 ces by mixing the manure with ashes before spreading 

 it abroad. 



A matter to be remembered is that if superphos- 

 phate is mixed with nitrate of lime, the mixture should 

 be made use of immediately; for if it is kept, its manu- 

 rial value decreases owing to the chemical actions that 



take place. 



^ 



Manuring and Milk Production. 



The Agricultural Neivs. Vol. X, p. 283, contained 

 an article which presented the results of experiments 

 that had been carried out for the purpose of ascertaining 

 the effect of certain kinds of manure on the produc- 

 tion of mutton. In the Journal of (he Board of Agri- 

 culture for January 1911, attention is given to 

 similar experiments that were made at the Midland 

 Agricultural and Dairy College, with the object of 

 obtaining similar information with respect to the way 

 in which pastures should be manured, under the condi- 

 tions of the experiment, in order to increase the pro- 

 duction of milk. The special manures employed were 

 superphosphate and sulphate of potash. 



The soil employed in the trials was of a strong, 

 clayey nature, and, on account of indications of a lack 

 of lime, both the manured and the control plot were 

 given a preliminary treatment in the form of an appli- 

 cation of 10 cwt. of ground lime per acre. The manurial 

 treatment consisted in the application of 4 cwt. of 

 superphosphate and lA cwt. of sulphate of potash per 

 acre. The procedure followed was to graze two cows 

 on each plot for a fortnight; after this they were changed 

 over, so that those on the manured plot now fed on the 

 unmanured plot, and vice versa. These changes con- 

 tinued for five months: thus each lot of cows visited 

 each plot five times. The yield of milk was only 

 observed during the second week of each fortnight, in 

 order to enable the cows, at every change, to get used 

 to the fresh conditions of pasture. 



In the result, the condition of the manured plot was 

 so much better than that of the other, that a third cow 

 was kept on it during the latter part of the experiment, 

 and a gain, due to the use of the manure, was obtained 

 to the value of 13s. per acre. It is held that this gain 

 would have been even greater in practice, as in the 

 experiment, the yield from the cows suffered periodically 

 from their removal to the inferior pasture, so that time 

 was required for this to be made up before the effect 

 of the improved conditions could be shown. 



