Miscellaneous. 



443 



[May, 1910. 



getting in Mexico, Central America and 

 Africa ; teak in India ; the forests and 

 lumbermen of Japan, the Philippines, 

 Australia and New Zealand. 



The Forms of Carbon. — The Great 

 diamond mines of South Africa, show- 

 ing how the diamonds are taken from 

 the ground, separated from the blue 

 clay, graded and cut. The graphite 

 pits of Ceylon. Coal mines and miners 

 of Pennsylvania and other sections of 

 the United States, of Europe and 

 Australia. Petroleum wells and refining 

 in various parts of the world. 



Transportation in all Lands.— How 

 people travel and carry their goods in 

 different parts of our own land and in 

 foreign countries. Transporting of com- 

 mercial materials by men, by pack 

 animals, and by primitive carts and 

 boats in Asia and Africa ; modern steam- 

 ships and railways in Europe and 

 America. 



For Advanced Grades. 



Lectures may be arranged on any of 

 the special subjects enumerated in this 

 circular, or on such subjects as Cotton, 

 Wool, Sugar, Spices, Beverages, Rubber, 

 Fisheries, Fruit Industries, etc. These 

 lectures describe the production of the 

 raw material, its preparation for man's 

 use, the countries of production, and 

 the importance of the material in the 

 commerce of our own and other coun- 

 tries. Other lectures may be chosen on 

 subjects of special commercial interest 

 such as Important Harbours of the 

 World, Ancient and Modern Trade 

 Routes, the Commerce of South America, 

 Foreign Business Methods, etc. 



Special Lectures. 



Free Public Lectures on • topics of 

 popular interest will be given at the 

 Museums as usual during the Winter. 



See separate announcement. 



Several School Extension Lectures will 

 be given in the Museums ' Lecture Hall 

 during the winter as a part of the course 

 offered by the Free Library of Philadel- 

 phia. 



ELEMENTARY PRINCIPLES OF 

 MANURING. 



(From the Indian Agriculturist, Vol. 

 XXXIV., No. 4, April, 1909.) 



Plants, like all other living organisms, 

 require nutriment, and according to the 

 supply of this nutriment will their 

 development be. 



Plants absorb food in the fluid state 

 only, either as gas or liquid. The gas is 

 carbon dioxide ("caibonic acid gas") 



which exists in the air. A few plants 

 are credited with absorbing nitrogen. 

 The other nutriment is absorbed in 

 solution in water. 



If an ordinary plant be very carefully 

 dug up with all the earth adhering to 

 the roots, and the earth be then care- 

 fully washed off, it will be found that 

 there is a main root (perhaps several). 

 This main root branches again and again, 

 giving off smaller roots, until finally 

 very fine hair-like processes are seen : 

 these ire the " root-hairs," and through 

 these root-hairs the plant absorbs all its 

 liquid nutriment. A land plant without 

 root-hairs cannot live; and hence the 

 necessity of great care in transplanting 

 young plants. Thus it is very important 

 to have a loamy soft soil for these root- 

 hairs to ramify into and obtain nourish- 

 ment in the neighbourhood of the root. 



Water. — Herbaceous plants may con- 

 sist of from 60 to 80 per cent, of water, 

 hence an adequate supply of water is 

 essential. In arid districts the water 

 question is the most important, but 

 with energy the difficulty can be over- 

 come to a considerable extent. 



By a process known as " dry farming " 

 a huge tract of barren land has been 

 recently brought under cultivation in 

 America. It was pointed out that soon 

 after rainfall on this land, thousands of 

 tons of water evaporated which might 

 be retained in the soil if proper cultiva- 

 tion were practised. The process of 

 retention consit?ts simply of preserving a 

 good open soil by deep cultivation and 

 constant hoeing of the surface to preserve 

 a fine tilth layer of well broken soil on 

 the surface, which tends to prevent 

 watar coming to the surface from below 

 to any great extent, and to keep it 

 imprisoned in the soil for the use of the 

 roots of plants. Of course " dry farm- 

 ing " means hard work, and the habits of 

 the Indian cultivator are not ordinarily 

 such as to benefit them for this kind of 

 farming. The hoeing has to go on con- 

 tinually. 



The following elements are essential to 

 plant life, besides the elements men- 

 tioned above as contained in water, viz:, 

 hydrogen and oxygen, and in carbon 

 dioxide, viz., carbon and oxygen :— 



Non-metallic— Nitrogen, sulphur, phos- 

 phorus. 



Metallic— Potash, calcium, magnesium, 

 iron. 



Nitrogen— Is a constituent element of 

 what are called " nitrates." These 

 nitrates usually resemble ordinary salt 

 that one uses at table. Nitrate of soda 

 or Chili saltpetre is an example of a 

 nitrate ; it is used as a f ertilizer or 



