UNITED STATES DEPARTMENT OF AS RIGUET ORE 
Contribution from the Bureau of Soils 
MILTON WHITNEY, Chief 
Washington, D. C. PROFESSIONAL PAPER September 28, 1915 
CONTENTS. 
Page. | Page. 
Ae PROMUCHOM Meta se ccs a Tek wea ant en -.s 1 | New modification of the chamber process __- 9 
PMerhodsohumamutachwne me sseee seers eee 2 | HactonyconsiderationSse= sees sso 13 
Measurement of a plant’s efficiency --..-.-.-.--- SRI PAD PEN Gixescsece eee PS eae TAU as a 15 
THE PRODUCTION OF SULPHURIC ACID AND A PROPOSED 
NEW METHOD OF MANUFACTURE. 
By Wit1u1am H. Waceaman, Scientist in Fertilizer Investigations. 
INTRODUCTION. 
The importance of sulphuric acid in science, arts, and manufacture 
has been increasing steadily for many years. Although scarcely any 
industry exists which does not employ this acid either directly or 
indirectly in the manufacture of its product,’ the bulk of the sul- 
phuric acid produced, both in this country and abroad, is used in the 
manufacture of fertilizer materials. 
- Since Liebig first proposed the treatment of bones or phosphate 
Sok with salig nce acid in order to render the phosphoric acid pres- 
ent water soluble, superphosphate has been the basis of the fertilizer 
industry, and the economic production of sulphuric acid has been 
‘the aim of numerous investigators and chemical engineers. . The pro- 
duction of sulphuric acid of various strengths in the United States for 
the past three years, according to the figures of the United States Geo- ~ 
logical Survey, is given in Table I. 
Because of the difficulty in shipping such a commodity all of the 
sulphuric acid produced is consumed in this country. Some of the 
products manufactured therefrom are shipped abroad but the quantity 
of acid entering into them is but a small percentage of the total 
production. 
In 1913 the United States consumed 1,931,468 short tons of phos- 
_ phate rock. Since practically all of this was made into acid phos- 
1 Phalen, W.C. Mineral Resources (1913). 
527°—Bull. 283—15——1 
