THE SCHUMANN RAYS AS AN AGENT FOR THE 
STERILIZATION OF LIQUIDS 
W. T. Bovier 
(WITH ONE FIGURE) 
The early investigators were unsuccessful in their attempts 
to use light as a sterilizing agent, partly because of a lack of knowl- 
edge concerning the nature of the action of ultra-violet light upon 
living organisms, and partly because of the inefficiency of the 
sources of light at their command. 
Fuxsen and his co-workers greatly extended our knowledge of the 
action of ultra-violet light upon living organisms, and Kucu (6) 
in 1905 (working in the laboratories of the firm of W. C. HERAEUS) 
invented the quartz mercury vapor arc, a source of light very rich _ 
in the ultra-violet rays. 
Nocier and THEVENOT (8) in 1908 were the first to make use 
of the quartz mercury vapor arc in the study of the biological 
action of light, and Courmont and Nocier (3) in 1909 advocated 
the use of the quartz mercury vapor are for the commercial sterili- 
zation of potable waters. They found that water which was 
contaminated with Bacillus coli and B. Eberth was sterilized in 
1-2 minutes by a quartz mercury vapor lamp 3 dm. in length, 
using 9 amperes of current. The water passed through an iron 
tube which inclosed the quartz lamp. 
In the same year Henri and Sropet (5) claimed to have 
sterilized milk with a quartz mercury vapor lamp. They per- 
formed many experiments and were certain that the milk was 
sterilized and that there were no bad effects on the milk such as 
are produced in the sterilization of milk by heat. 
CourMont and Nocter (2) pointed out the fact that ultra- 
violet light does not penetrate colloidal solutions, and Dornic and 
DarreE (4), in a paper on the use of ultra-violet rays for sterilization 
in the brewing industries, pointed out that the light could not 
sufficiently penetrate milk or cream to sterilize them, and that, 
Botanical Gazette, vol. 60] {144 
