Jtwe I, 1883.] 



tHE TROPICAL AGRICULTURIST. 



MS 



readily to com))inations with acids of that series, and also 

 with many of the coloiu-ing matters. Let any one take 

 a sample of cinchona bark, and mix it with potash soila, 

 or ammonia, and another portion and mix it with lime, 

 and prepare a tinctm-e from each mixture ; the tlifference 

 of colouring of the two mixtures would be astonishing. 

 Of com-se an operator conducting an experiment with 

 lime and a bark would take care that he did not carry 

 his temperatme too high. It was possible to exhaust cin- 

 chona Ijark with hme and alcohol at a normal temper- 

 atui'e, provided that the bark and the lime were in a pro- 

 per state of division. He did not say that lime was 

 adapted all round under all circumstances ; but under cert- 

 ain eucumstanccs it was the best agent. Especially was 

 it the best thing for beberiue. He had lately had a bark 

 sent to him from the west coast of Africa, and he had 

 experimented upon it with various alkalies, but the found 

 lime the l>est of all. He should like to ask Mr. Nayl- 

 or whether he prepared the hydi'obromide or the phos- 

 phate of the alkaloid. Those salts usually yielded them- 

 selves very readily to crystallization, and as a rule they 

 were insoluble in cold alcohol, but they dissolved readily 

 in hot alcohol, from which they were generallj' deposited 

 upon coohug in a crystalhue from. That was, in his 

 opinion, one of the best methods of obtaining a piu-e 

 crystalline salt of an alkaloid. He should like to know 

 what cjuantity of bark Mr. Naylor operated npon, as the 

 quantity made a considerable thffereuce in the investigation 

 It was not possible to carry out a thoroughly exhaustive 

 investigation with a small quantity ; from 7 to 14 pomids 

 - were needed for a full investigation. 



Mr. Luff remarked that Mr. Gerrard had not brought 

 forward any exijerimental evidence that lime did not 

 bring about the decomposition which he (Mr. Luff) had 

 mentioned. 



Mr. Taxxer said he should hke to ask whether Mr. 

 Naylor had examined the liquid from which the precipit- 

 ate was obtained, and whether he concluded that by the 

 precipitation of the body which appeared to be allied to 

 paricine he had separated all the alkaloidal constituents. 

 If not, Mr. Naylor's results and those obtained by Mr. 

 Broughton might be brought into accordance. It was 

 known that when alkaloids were precipitated with caustic 

 soda or potash, the residual liquor might contain another 

 body, even lesculin. or the product jesculetin. "With re- 

 gard to the non-crystallizability of the alkaloid, he should 

 like to ask what solvents Mr. Naylor employed, for it was 

 kno\vu that in some cases the addition of a body ha\-ing 

 a less solvent action on the alkaloid than the one in 

 which it was dissolved would determine crystaUizatiou. 



Mr. Navi.or, in reply, said in reference to the remarks 

 of Mr. Luff, that he did not think that any process which 

 could be devised wovUd be suitable for the extraction of 

 an alkaloid in every instance. Had he not been pretty 

 certain from preliminary investigations that the alkaloid 

 in ([uestiou was very closely allied to beberine on the one 

 hand, and to quinine on the other, and fiu-ther, had he 

 not fouud the colomnng matter somewhat troublesome, he 

 certanily should not have employed such a process as the 

 lime process. That process was by no means original. 

 Not only was it largely employed for the extraction of 

 quinine from cinchona barks, but it was the process 

 which Dr. Hesse had himself made use of for the ex- 

 traction of paricine. He thoroughly agreed with what 

 Mr. CJeri'ard had said as to the use of lime, and he only 

 needed to emphasize his remarks on that point. Oxalic 

 aciil was perhaps about as sei"viccable an acid as could 

 be employed for the extraction in this case. It extracted 

 the alkaloid with probably the minimum amount of colonr- 

 ing matter, and it might be ad\nsahle. to employ a weak 

 solution of oxalic acid ; but decomposition took place very 

 largely in the heating of the body afterwards. In reply 

 to Mr. Gerrard. he might state that he did not prepare 

 the hydrobromidc, but he did prepare the phosphate, 

 though he did not succeed in getting it to crystallize. 

 The quantity of bark that he worked upon was 30O grams. 

 The bark was tested for .-esculin, but that body was not 

 found. The solvents employed were benzol, chloroform, 

 ether, petroleum spirit, acetic ether, organic acids and 

 mineral acids. As to ttmipOrature, he had employed vari- 

 ous temperatures ranging form (>0 ° to 120'^; and with 

 regard to time, the periods had varied from very short 



ones to periods of four or five days, with a temperature 

 of 110^ F. It was well known that paricine ha<l not yet 

 been obtained in the crystalline condition. He wished it 

 to be distinctly understood tliat he did not state that 

 the body which he had oljlJiined was paricine ; that point 

 remained for fiu-ther investigation. 



A vote of thanks to Mr. Naylor was then passed. — ■ 

 PhannacciUical Journal. 



VICTOKIA PLANTERS' ASSOCIATION, NATAL. 



TREE-PLANTING AND RAINFALL. 



Mr. AViikinson's paper, as follows, was then read: — 

 Tree-planting in its relation to the rainfall of the country, 

 and the kinds of trees most adapted to our coast chmate. 

 The subject of the influence of trees on rainfall has been 

 a gooil deal written on, and in a series of articles published 

 by Mr. A Fryer in the Sii(/ar Cane, the sxibject has been 

 very ably and exhaustively treated. Any one reading these 

 articles can come, I think, only to one conclusion. I pro- 

 pose in this paper to make a few extracts from them, 

 and must refer any one requiring more information to 

 Ml". Fryer's papers in vols. 4, 5 and 6 of the Sugar Cane. 

 In many countries and districts which once were celebrated 

 for their fertility, agriculture cannot now be carried on at 

 all on accoimt of the diminished rainfall, consequent on 

 denuding the country of forests and bush — for instance 

 Palestine, the northern shores of the Mediterranean, Greece, 

 and parts of Spain. The mountains of Estremadura and 

 Mureix have been stripped of their forests, and there is 

 now no rain there for eight to ten months, which forbids 

 agriculture ; while Catalonia and Valencia are covered with 

 wood, and possess a moist and productive soil. Professor 

 Lindley observes of Mauritius: *'If this island should in 

 time become barren, it will only undergo the fate which 

 universally attends the destruction or absence of forest in 

 countries exposed to gi-eat solar heat." Blanqui says of 

 the Cape Verd Islands: " The terrible droughts which 

 devastate them must be attributed to the destruction of 

 the forests. On the other hand, in South America, there- 

 appearance of forest upon cleared land was followed l>y a 

 rising of the waters of Lake Tacaragua." Again Blanqui 

 says : " In St. Helena the wooded sm-face has extended 

 and the rain has increased in proportion. It is now double 

 what it was during the residence of Napoleon." The same 

 authority says : "■ In Egypt recent plantations have caused 

 rain. The rainfall in Egj'pt was as low as \2'\\\. a year, 

 but by the planting of some milliojis of trees by ^lahamet 

 Ali the rainfall has been brought up to 40iii. This is a 

 quantity at which sugar can be proiitably grown, although 

 50 in. would be better; in some of the more favoured 

 stations in Maiu-itius the rainfall is over TOin. '^^'hen the 

 Mormons firft settled iu Ut^h tliey found the district 

 barren; water had to be brought ah iiost incredible distances 

 in wooden pipes; trees were carefidly planted and nomished 

 with the water so brought, and now the district maybe 

 termed the garden of the world, and is not dependent on 

 water brought a di.stancc, but enjoys a steady rainfall.*' 

 In Ascension, the re-planting of it mountain caused a s|>ring 

 which had dried up after fclUng the wood to flow again 

 with its former abundance, the wood having bi-en cut down 

 on the sides of the mountain had dried up the spring at 

 its base. The fallowing is from *'l*roetor's Light Science*'; — 

 " AVe may point out in this place the important connection 

 which exists between the rainfall of a country and the 

 amount of forest land. "We notice that in parts of America 

 attention is being paid with marked good results to the 

 influence of forests in encouraging rainfall. AVe have here 

 an instance in which c-avise and eliect are interchangable. 

 Rain encoiu-ages the growth of an almndant vegetation, and 

 abundant vegetation in town aids to produce a stat<; of 

 the superiufumbeut atmosplrere, which encouiages the pre- 

 cipitation of rain. The consequence is, that it is very 

 necessary to check, before it is too late, the processes which 

 lead to the gradual tlestructiou of forest*. If these pro- 

 cesses are continued, and the climate lias become ex- 

 cessively dry, it is almost impossible to remedy the mis- 

 chief, sinqdy because the want of moisture is destructive 

 to th(! trees which nuiy he planted to enco\u'agi' rainfall. 

 Tbvis, there are few processes more ditiicult (as has been 

 fouud in parts of Spain and elsewhere) than the change of 

 an arid region into a vegetation covereil di»liiet. Iu fact, 



