RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



The production of sulphuric acid and a proposed new method of manu- 

 facture, W, H. Waggaman (C7. S. Dept. Agr. Bui. 283 {1915), pp. 39, fig. 1).— 

 The first pages of this bulletin deal with a general consideration of the manu- 

 facture of sulphuric acid, statistical data and discussions of the principles of the 

 two general methods of manufacture — the contact process and the lead-chamber 

 process — being given. A critical discussion is given of a number of modifica- 

 tions of the chamber process which have been employed more or less successfully 

 to secure a thorough mixing of the gases involved in the reaction and for con- 

 trolling their temperature, these two conditions being essential for the efficient 

 operation of a plant. 



The author describes a new modification of the chamber process for the manu- 

 facture of sulphuric acid. This modified method is designed to secure a complete 

 mixture of the gases and control of the temperature without the use of excessive 

 and complicated apparatus. It is stated that while the 7nethod has been tried out 

 only in the laboratory, the results obtained indicate that it would probably be 

 successful if worked on a factory scale. 



" This method is based on the fact that if a mixture of warm gases is drawn 

 downward through a special flue their resistance to the downward pull, together 

 with the constant change of their course, will tend to mix them very intimately, 

 and unless the internal diameter of the flue is too great there will be practically 

 no zones of inactivity in the apparatus. Moreover, the constant impinging of 

 the gases on the walls of the spiral flue, which can be cooled either by air or 

 water, makes it practicable to maintain the gases at a temperature most favor- 

 able for the efiicient yield of sulphuric acid." 



The process was carried out in the laboratory as follows: The air, steam, 

 sulphur dioxid, and oxids of nitrogen were given a preliminary mixing by being 

 passed through a 200 cc. test tube containing a small amount of water heated 

 to boiling. The mixed gases were then drawn into the lead spiral, which takes 

 the place of the lead chambers in the process as ordinarly carried out. Most 

 of the sulphuric acid produced in the system was formed in the lead coil, which 

 was heated to about 90° C. The residual gases were then passed through ab- 

 sorption bulbs containing strong nitric acid to absorb the sulphur dioxid which 

 had escaped oxidation in the spiral. Full data are given regarding the quan- 

 tities of sulphuric acid produced in these laboratory experiments. 



In considering the construction of a sulphuric-acid plant based on the appa- 

 ratus described, the author states that the lead spiral is intended to replace only 

 the lead chambers and intermediate towers and is not intended to replace the 

 Glover or Gay-Lussac towers. Application has been made for a public-service 

 patent covering the process. 



The appendix of the publication contains a classification of brief abstracts of 

 American patents on the manufacture of sulphuric acid. 



Hardened oils, E. Mellana {Ann. Chim. Appl. [Rome], 1 {1914), No. 9-10, 

 pp. 381-387) .—Cotton seed, soy bean, kapok seed, whale, and sperm oils were 

 hydrogenated, nickel being used as the catalyst, and the properties of the re- 



9 



