74 SELECT PLANTS FOR INDUSTRIAL CULTURE 



cultivated on the mountains of Bengal. It has heen found 

 hardy in Lower Gippsland and the Westernport District. It 

 grew in Madeira at an elevation of 500 feet, after having been 

 planted two and a half years, to a height of 20 feet, flowering 

 freely. All these cinchonas promise to become of importance 

 for culture in the warmest regions of extra-tropical countries, 

 on places not readily accessible or eligible for cereal culture. 

 The Peruvian proverb that cinchona trees like to be " within 

 sight of snow " gives some clue to the conditions under which 

 they thrive best. They delight in the shelter of forests, 'where 

 there is an equable temperature, no frost, some humidity at all 

 times both in air and soil, where the ground is deep and 

 largely consists of the remnants of decayed vegetable sub- 

 stances, and where the subsoil is open. Drippage from shelter 

 trees too near will be hurtful to the plants. Closed valleys 

 and deep gorges, into which cold air will sink, are also not 

 well adapted for cinchona culture. We ought to consociate 

 the Peru Bark plants with naturally-growing fern trees, but only 

 in the warmest valleys and richest soil. The best temperature 

 for cinchonas is from 53 to 66 F. ; but they mostly will 

 endure in open places a minimum of 32 F. ; in the brush 

 shades of the Botanic Garden of Melbourne, where years ago 

 cinchonas were already raised by the thousand, they have 

 even resisted uninjured a temperature of a few degrees less, 

 wherever the wind had no access, while under such very slight 

 cover the cinchonas withstood also a heat of a few degrees 

 over 100 F. The plants are most easily raised from seeds, 

 best under some cover such as mats, and they are seeding 

 copiously already several years after planting. The contents 

 of alkaloids in the bark can be much increased by artificial 

 treatment, if the bark is only removed on one side of the stem 

 and the denuded part covered with moss, under which in one 

 year as much bark is formed as otherwise requires three years' 

 growth, such forced bark, moreover, containing the astounding 

 quantity of as much as 25 per cent, alkaloids, because no loss of 

 these precious substances takes place by gradual disintegration 

 through age. The root bark of some cinchonas has proved 

 to contain as much as 8 per cent, of alkaloids (see Gardeners' 

 Chronicle, 1877, p. 212). The income from Java plantations 

 is considerably over double the cost of the expenses of culture 

 and transit. Mr. Howard's opinion that cinchonas in low 

 land plantations produce a far less quantity of alkaloids needs 

 further confirmation, particularly regarding the valuable 

 quinin and cinchonidin. The cinchona plants are set out at 

 distances of about 6 feet. The harvest of bark begins in the 

 fourth or fifth year. The price varies in Europe from 2*. to 



