4 So 



THE TROPICAL AGRICULTURIST. 



[December i, 1882. 



quantity. LTuder these circumstances, it is evident 

 tliat in Mauritius there ought to be a good opening 

 for the introduction of Ekmau's system even thouyh 

 the bi-snlphate of mignesia should have to be im- 

 ported fr'mi hence or from India. It is quite possi- 

 ble also that magnesite might be fouud on the island. 

 — Planters' Gazette. 



MICA. 



An adverliscment in the Ceylon Observer recently, 

 indicated that this article is in request, and just 

 as we were speculating over the purpose to which 

 it is applied, we came across the following notice in 

 an Auierituu journal : — 



" Mica Axle Grease, Patented, 1874— Composed 

 largely of powdered Mica or Isinglass, is the best and 

 cheapest lubricator, in the world — the best because it 

 does not gum, but forms a highly polished surface over 

 the axle, reducing friction and lightening the draft ; the 

 cheapest because it costs no more than inferior brands, 

 and one box will do the work of two of any other make. 

 Answers as well for Harvesters, Mill Gearing, Thresh- 

 ing Machines, Coru-Planters, Carriages, Buggies, etc., 

 as for "Wagons. Guaranteed to contain no Petroleum." 



By a further curious coincidence, we have come 

 across the following paragraph : — 



"One of the chief Ui-es of mica at the present time 

 is for stove doors aud lanterns, the tire resisting qual- 

 ities of the miuer.vl together with its transparency 

 rendering it specially adapted for the purpose. But 

 only the very clearest and best sheets of mica can be 

 thus used. Vast beds of the substance exist in various 

 parts of the country, for which, except the finest por- 

 tints, as above mentioned, there is little demand. 

 New uses will, however, doubtless be discovered and 

 invented, tor mica is made up of valuable material?. 

 We notice among tlie recently granted patents two 

 inventions iu this line. Oae is for the manufaclure 

 of j'lurnal boxes of cement, grouud mica and fl lur ; 

 the ingredients are mixed, pree.sed into shape, and 

 then baked. The other is an apparatus for reducing 

 mica to an impalpable powder and preparing it for use 

 as a mixer in starch gloss and oily compositions. 



" Chemically regarded mica is made of silica, alumina 

 and potash. "Silica is one of the hardest substances 

 in niture, known in its purest and most beautiful form 

 as rock crystal. Alumina is anolher excei dingly hard 

 substance. One of its most useful but impure forms 

 is emery or corundum, now so extensively employed for 

 grinding and polishing purposes. The most elegant 

 and purest examples of sdica .nre seen in the well 

 known precious stouef, the ruby and the sapphire. 

 Potash, the remaining ingredient of mica, is familiar 

 to everybody, and is extensively used in the aris. 

 Our coiiiniercial suppbes of potiinh chiefly come from 

 the ashes of plants and trees, and their roots take it 

 from the grouud, the granite rocks being the original 

 source. Granite is composed of quartz, feldspar aud 

 mica. " — Scientific A merican. 



Mica is very plentiful in Ceylon, but, as far as our 

 observation goes, not iu large sheets or in a tenacious 

 form. Most of what we have seen has been in a 

 crumbly state. When going round the new Nuwara 

 Eliya drive to the right of the Barracks Plain about 

 three years ago, we saw a large collection of pieces, 

 of pretty good size some of them, glancing in the 

 sun. We need scarcely tell our readers that the 

 more felspar and mica abound iu our gneiss the richer 

 are they in potash, and, if pieces of such rock could 

 be cheaply broken and pounded, a valuable applica- 

 tion to the soil would be at hand. Is plumbago 

 still used in Ceylon mixed with oil or grease as a 

 lubricant for machinery ? We were told iu Mel- 

 bourns, that it w.-w t99'li2ati°c- *I'''^' "otwitlistaud- 



ing the silica in its composition, may give less fric- 

 tion. In an elaborate article we read recently on 

 lubricating oils, the preference was given to sperm, 

 but mineral oils were said to answer well. It it 

 curious that mica should be used as an ingredient 

 in two such opposite substances as cement and strach 

 gloss. Our readers are aware that the kirimefti of 

 the Sinhalese — kaolin, China clay or pipe clay — is 

 the result of decomposed felspar, arid that the sub- 

 stance crystallizes into moonstone ; wdiile alumina, in 

 other words clay, is the source of the precious stones, 

 which, according as they are coloured, are called 

 rubies or sapphires. It is by a slip of the pen, 

 we fancy that the wi-iter in the " Scientific American" 

 mentions those gems as the most elegant and the 

 purest forms of silica. He had previously and cor- 

 rectly represented silica as known in its purest and 

 most beautiful form as rock crystal. Rubies and 

 sapphires are crystallized clay. Judging by appear- 

 ance, we should suppose that asbestos, which 

 resists fire even better than plumbago or mica, must 

 have some affinity to the latter, only that asbestos 

 seems to have no tendency to decompose. Asbestos 

 is mineralogically described as "a variety of horn- 

 blende and pyroxene, " occurring in long delicate fibres 

 or fibrous masses. 



THE CEYLON TEA ENTERPRIZE. 

 It may be, looking at the averages obtained in the 

 Indian tea districts in India, that the estimates of pro- 

 bable returns : — 700 lb. of tea per acre for low estates 

 and 400 lb. for those at high altitudes (4,000 feet and 

 upwards) — were over-sanguine. We know, in regard 

 to other cultures, how insect and fungiis pests and ab- 

 normal weather may disappoint even the most cautious 

 estimates. On the other hand the damp, hot forcing 

 climate of Ceylon must be taken into account. India 

 is a continent and most of the tea produced there is 

 grown outside the tropics — about 27° north. Ceylon is 

 an island, with a climate of combined heat and damp 

 and the region in which tea is being cultivated ranges 

 about 7° only from the equator. The conditions for 

 luxuriant vegetation could scarcely be better. The 

 estunates of the Indian Tea Planter, therefore, may 

 not be so " reckless " as the writer who appropriates 

 nearly a sixth of the alphabet when denouncing ex- 

 travagance, may imagine. We cannot say whether or 

 not our correspondent ' ' Clha " had any pai-ticular 

 estates in view when he condemned the sending of 

 rubbish into the market. He certainly did not name 

 any. The reputation of Loolecondera is fully established 

 but nothing could be less germane to D. W. F. L.'s 

 argument than, the high prices obtained for tea from this 

 higli estate. Until the art of tea-making is thoroughly 

 understood everywhere in ('eylou, comparisons are not 

 only odious but utterly valueless as settling the ques- 

 tion of the respective merits of low-grown and high 

 grown tea. We have seen and tasted tea of excellent 

 quality grown a few feet above sea-level, while 

 " rubbish " has been turned out on high estates " 

 and rice rersa. The question hitherto has been sim- 

 ply one of preparation. But taking into account not 

 only the theoretical belief in the influence of high 

 altitude on flavour, but also the now loug-continued 

 experience of Ilarjiling, and the Kangi-a Valley, 

 there can be no doulit that the Indian tea planter 

 was perfectly justified in anticipating that, when tea 

 is equally well made on high estates and low, the 

 more delicate flavour of the high-grown leaf will 

 bring compensation in the market for the considerably 

 Enialler yield when compared with that obtained on 

 Jow estates. 



