feo6 



THE TROPICAL AGRlCOLTURIS'f. 



[Mav I. 1886. 



But neither ju agriculture nor in manufactures 

 can salt be profitably used to any considerable 

 extent unless the duty is removed. To do this, 

 so as to leave the salt revenue unaffected — and 

 India can ill-afford to lose it at the present junc- 

 ture — it is necessary to discover some method of 

 renderint^ salt unfit for human consumption with- 

 out aiieclini; its suitability for employment in other 

 directions. In those European countries in which 

 salt is still taxed, this problem has been satisfac- 

 torily solved. In Germany, salt is denaturalized 

 by the mixture of oxide of iron, and vermouth 

 powdsr, or charcoal, when it is intended for cattle, 

 and by the addition of charcoal, ashes, lamp-black, 

 or ordinary soot in the case of salt required for 

 manure. In France, the denaturalizing agents used 

 are very numerous, but salt intended for manure 

 is, as a rule, mixed with poudrette. None of these 

 processes are, however, suitable to the conditions 

 obtaining in India, where the duty is much heavier, 

 and where the powerful tropical sun renders the 

 process of lixiviation extremely easy. It would 

 indeed be jjossible to use the poudrette i^rocess, 

 but the Government of India considers that the 

 issue of a mixture of the kind to the people of 

 this country is obviously objectionable as leading 

 to serious misapprehension of motives. The sug- 

 gestion was made by the Commissioner of Salt 

 llevenue in Madras, and suijported by the Madras 

 Board of Bevenue, and we doubt whether, so far 

 as the Southern Presidency is concerned, the ob- 

 jection taken by the Government of India is well- 

 founded. There could, in any case, be no mis- 

 apprehension of motives by coffee-planters, and 

 Mr. Bliss's proposal referred to salt required for 

 a patent manure, which was primarily intended 

 tor coffee gardens, and was not likely to be patrou- 

 ized by the ryot. The Government of India, how- 

 ever, rejected the Madras suggestion, and since 

 then the chemists of Bengal, Assam, and Burmah 

 have been endeavouring, but without success, to 

 discover a process which will fulfil the conditionj 

 laid down by the Supreme Government. The latter 

 has accordingly just published a resolution on the 

 subject, and has offered a reward not exceeding 

 B5,00U to the inventor, or discoverer of a process 

 which will satisfy the main conditions. These are 

 that the cost of the process must not exceed four 

 annas a maund, and the preparation nmst be such 

 "that edible salt connot be inolUably extracted from 

 it by any of the ordinary processes in use amongst 

 native salt-workers. The conditions are extremely 

 difficult. All the organic, and many of the inorganic 

 substances suggested as denaturalizing agents are 

 liable to be destroyed by a degree of heat too 

 low to affect salt. To be really effective, the sub- 

 stance added to the salt must be chemically similar 

 to it, and must, at the same time, be of low price. 

 None of the substances detailed in the Resolution 

 now before us fulfil these conditions, though that 

 advocated by Dr. Bomanis goes near to doing so. 

 He proposes a mixture of salt and the sulph-anti- 

 muriate of sodium (Sohlippe's salt) the solubility 

 of which is nearly the same as that of common 

 salt. Salts of antimony act as emetics on human 

 beings, but have no such effect on tattle and 

 horses, so that the preparation would not compete 

 with edible salt. This process was rejected on the 

 gi-ound that antimony acts as a cumulative poison, 

 and that fatal effects would follow its continued 

 use. Dr. Bomanis has, however, in the columns 

 of the Indian Aiiriciiltnrifl, denied this, and states 

 that he presumes the idea was S'lggested by tlie 

 analogy of arsenic. This is a question, however, 

 which we nuist leave the chemists to decide. 



The Government of India seems to us to be 

 uudul> uervQuu regardiug itij leveuue. Salt can 



easily be so discoloured that any attempt to publicly 

 sell the denaturalized article would be discovered 

 without difficulty. lu this rresidcncy it is only 

 on the coast that any extensive attempt would be 

 made to recover common salt from it, and surely 

 a Department of which the subordinate agents are 

 so vigilant that they recently obtained the con- 

 viction of an old woman foi' being in the possession 

 of illicit salt when she was in reality only taking 

 home her husband's ashes, is sufliciently powerful 

 to prevent the success of any endeavour on a large 

 scale to evade the Salt Laws. The question is of 

 such importance that an experiment might well 

 be made to see whether the issue of prepared salt, 

 free of duty, would have any appreciable effect 

 on tlie revenue, and we would suggest that it should 

 be undertaken by the Madras Salt Department, 

 the organisation of which is inferior lo none in 

 India.— J/arf?'«s 3Iail. 



TEA CHESTS: CORROSION OE LEAD 

 LININGS. 



The " Journal of the Asiatic Society of Bengal," 

 issued on 'iilth December last, contains a " Memor- 

 andum on the Corrosion of the Lead Linings of 

 Indian Tea Chests, by Alex-Pedler, i.c.s., Professor 

 of Chemistry in the Presidency College. Calcutta,' 

 which shows that very careful and intelligent ex- 

 periments were made. The result is summed up 

 as follows : — 



The conclusious that my experiments have led lue 

 ttf form are as follows : — 



1. That tea properly mauufactured in the ordinary 

 way has uo jjower to corrode lead. 



2. That if unseasoned aud damp wood is used for 

 the manufacture of the tea boxes, corrosion of the tea 

 lead is, under favourable circumstances, almost cer- 

 tain, but that some varieties of wood act more vio- 

 lently than others. 



3. That even if seasoned wood be used to make the 

 tea boxes, aud if il be nll'^wed to become saturated 

 with water, and then placed in favomablo circum- 

 stances of heat and moisture, corrosion of the tea lead 

 may occur, though not to so great an extent as if un- 

 seasoned wood liad been used. 



■1, That the active agsut does not exist ready formed 

 in unseasoned wood, but is produced by a secondary 

 action from the constituents of the wood. 



.'1. That the corrosion is not usually due to contact 

 action between the lead and the wood, but that a 

 volatile substance is gradually produced from the un- 

 seasoned wood. 



G. That the corroding agent is nsuilly acetic acid 

 in tlio presence of moist air aud carbonic acid, but that 

 other acids of the same series are sometimes produced 

 aud also act on the lead, and in the case of butyric 

 aud valeric acids a greeuish yellow incrustation is 

 formed differing entirely from the whitish or yel- 

 lowish incrustation produced from acetic acid. 



7. Thnt tht' acetic aud otheracids arc produced by 

 the decomposition (probably by a kiud of fermentution 

 imdcr the inffuonce of heat and moisture, and perhaps 

 started by decomposing nitrogenous matters) of cer- 

 tain substances which are known to be present in 

 woods. Such bodies are fermentable sugars, starchy 

 matters, malic acid, etc. 



8. That the lead linings nf the tea chests having 

 been corroded aud perforated by the corroding action 

 of these acids in the presence of moist air, and carbonic 

 acid, the tea can easily takeup the disagrecjb'e odour 

 which the wood itself will possess, after it has un- 

 dergone the change in which acetic and butyric acil, 

 etc., are formed, and thus the (juality of the tea will 

 be deteriorated. 



As a mailer of fact, very little, if anything ha-'- 

 recently been heard of damage to tea by unseasoned 

 OX damp woods iu teabosec. 



