THE IRRIGATION AGE. 



601 



sorbed by the leaves and roots in large quantities, hence 

 its presence in the atmosphere is necessary to plant 

 growth, though the proportion is small. 



Carbonic acid unites with potash, soda and lime, form- 

 ing compounds known as "carbonates." Thus pearlash is 

 carbonate of potash; the common soda of the shops is 

 carbonate of soda, and limestone or chalk is carbonate of 

 lime. The common carbonate of lime, in its various forms 

 of chalk, limestone or marble, is insoluble in pure water, 

 but it dissolves readily in water containing carbonic acid. 

 We know that water absorbs a quantity of carbonic acid 

 from the atmosphere, and hence as it trickles through the 

 soils containing limestone, etc., it dissolves a portion of 

 the earth and carries it in its progress to the roots of 

 the plants, where the earthy solution is used directly or 

 indirectly to promote vegetable growth. 



As to its absorption by water, a reference to a com- 

 mon glass of soda water will be sufficient to make this 

 clear. 



Some plants manufacture their own acids out of the 

 carbonic acid distinctive acids for instance, oxalic acid, 

 which is found in the leaves and stems of the common 

 sorrel (oxalis). It is an acid not found in the soil and 

 may be obtained from sugar, starch and even from wood 

 by various chemical processes, principally by the use of 

 nitric acid. To detail all the uses to which carbonic acid 

 may be put would be going deep into chemistry, which 

 is beyond the scope of this book. 



Ammonia. 



Ammonia is a compound of hydrogen and nitrogen, 

 and performs a very important part in the process of 

 vegetation. It promotes not only the rapidity and luxu- 

 riance of vegetation, but exercises a powerful control over 

 the functions of vegetable life. It possesses several special 

 properties which bear upon the preparation of plant food. 



First It has a powerful affinity for acid substances, 

 and unites with them in the soil, forming saline com- 

 pounds of "salts," which are more or less essential to 

 vegetable life. 



Second It possesses a very strong affinity for the 

 acids of potash, soda, lime and magnesia. When mixed 

 with these acids the acid in the salt of ammonia (sal am- 

 moniac), for instance, is taken up by the potash, etc., and 

 the ammonia is set free in a gaseous state. This is the 

 effect of lime dressing on a soil rich in animal and vege- 

 table matter; it decomposes the salts, particularly those of 

 ammonia. 



Third The salts which ammonia forms with the acids 

 are all very soluble in water, and thus ammonia is brought 

 down to the roots of plants for their use. 



Fourth In the state of carbonate it decomposes gyp- 

 sum, forming carbonate of lime (chalk) and sulphate of 

 ammonia, both of which are peculiarly favorable to vege- 

 tation. 



Fifth The presence of ammonia in a soil containing 

 animal and vegetable matter in a decaying state causes 

 this matter to attract oxygen from the air with great rap- 

 idity and in abundance, the result being that organic acid 

 compounds are formed which combine with the ammonia 

 to form ammoniacal salts. On the decomposition of 

 these latter salts by the action of lime or other of the affini- 

 ties above mentioned, the organic acids senarated from 

 them are always further advanced toward the state in 

 which they become fit for plant foods. 



Sixth -The most important property of ammonia is 

 the ease with which its salts undergo decomposition, either 

 in the air, in the soil or in the interior of plants, a pecu- 

 liarity which is possessed by water, as has been said. In 

 the interior of the plant ammonia separates into its con- 

 stituent elements as freely as water. The hydrogen it con- 

 tains in so large a quantity is always ready to separate 

 itself from the nitrogen, and so, in concert with the other 

 organic elements introduced into the plant through the 

 roots or the leaves, it aids in producing the different solid 

 bodies of which the several parts of the plant are made 

 up. The nitrogen also becomes fixed that is, "permanent" 

 in the colored petals of the flowers, in the seeds and in 

 other parts of the plant it passes off in the form of new 

 compounds, in the insensible form of perspiration, or in 

 perfumed exhalations of the plant. 



(Continued on page 630.) 



Pittsburgh Land Show 

 Open 17th to 29th 



By Sydney Wire 



The Pittsburgh Land Show opened Monday, the 17th, 

 and an enormous attendance is expected. The building, 

 which is known as Duquesne Garden, will be gorgeously 

 decorated for the occasion and the massed bands of the 

 Pennsylvania State Militia and Naval Volunteers will fur- 

 nish band concerts during the afternoon and evening. An 

 excellent variety of exhibits have been secured by the 

 committee of organization and train loads of fresh fruit 

 and vegetable products are daily pouring into Pittsburg 

 and are being installed in the exhibition building. The 

 state of Colorado, as well as that of California, will be 

 suitably represented with large exhibits, while the indus- 

 trial departments of a number of the larger transcon- 

 tinental railroads are vicing with each other in an effort 

 to surpass in the splendor and magnitude of their respec- 

 tive exhibits. A great deal of attention is being paid to 

 the educational department of the show and an auditorium 

 has been set aside for the presentation of stereoptican 

 views and moving pictures and for the delivery of special 

 lectures, which will cover a multitude of subjects pertain- 

 ing to the land and which will be delivered by government 

 lecturers who will be sent from Washington for that pur- 

 pose. The Pittsburgh Land Show will have another feature 

 which is creating a vast amount of national interest and 

 which will probably bring to a conclusion the controversy 

 referring to the ultimate location of theWorld's Panama 

 Exposition to be held in 1915 in honor of the inaugural 

 and opening of the navigable passage which will join the 

 South Atlantic Ocean with the Pacific and which will ma- 

 terially change the present existing conditions of the 

 world's maritime commerce. There is a heated discussion 

 now progressing between the rival factions of Louisiana 

 and California, and a powerful syndicate has been formed 

 in the South which is headed by Gov. Jared Y. Sanders of 

 Louisiana, who is supported by Mayor Bahrman of New 

 Orleans and an influential faction of state offiicals and 

 other well known people. The Louisiana forces will in- 

 vade the East, making their congressional headquarters at 

 the Pittsburgh Land Show, where they have secured five 

 hundred square feet of space in which they will display 

 photos and pictures of Louisiana, views of New Orleans 

 and an interesting array of the semi-tropical plants of 

 Louisiana with samples of corn, sugar cane, cotton, rice 

 and tobacco, while a small army of notable speakers will 

 accompany the delegation and a strong effort will be made 

 to secure the votes and co-operation of the Philadelphia 

 delegation in Congress. Among the official speakers for 

 the World's Panama Exposition will be Gov. Jared Y. 

 Sanders of Louisiana, Robert Glenk, Curator of the 

 Louisiana State Museum and Chairman of the Committee 

 of Exhibition and Sam Blum, Chairman of the Committee 

 of Publicity. The Pittsburgh show is going to be a big one, 

 and the entire community has been staggered by the in- 

 undation of billing matter and the wide reach of the pub- 

 licity which has practically covered four of the most 

 densely populated states in the Union. THE IRRIGATION AGE 

 has secured space at the exposition and will be adequately 

 represented with a suitable exhibit. 



It is proposed to make the Pittsburgh Land Show an 

 annual event and a number of the local papers are willingly 

 offering their editorial co-operation. Any further informa- 

 tion concerning the Pittsburgh show can be obtained by 

 addressing the Administration Department at their offices 

 at the Keystone Bank Building, Pittsburgh, Pa. 



Send $2.50 for the Irrigation Age 1 year, and y 



cloth bound copy of the Primer of Irrigation X 



* 



