220 A MANUAL OF BACTERIOLOGY 



essential oil secreted by the trees contains a hydro- 

 carbon C 10 H 16 ; and as this is vapourised, it is re- 

 solved in the presence of atmospheric oxygen and 

 moisture into camphoric peroxide, camphoric acid, 

 and hydrogen dioxide l : 



(a) 2 10 H 16 +50 2 = 2C 10 H 14 4 +2H 2 0, 

 (/9) C 10 H 14 4 +2H 2 = C 10 H 16 4 +H 2 2 ; 

 and it is the hydrogen dioxide, so produced, which 

 destroys the microbia of malaria. 



In the treatment of malaria certain medicinal 

 substances are used. (1) Tommasi-Crudeli 2 recom- 

 mends arsenious acid in small doses ; and, according 

 to many English authorities, Fowler's solution (con- 

 taining 1 part of arsenious acid in 120 parts of water) 

 should be prescribed in 5 to 10 minim doses three 

 times a day. (2) Quinine salts, in large doses, have 

 also been recommended, especially by travellers 

 who have had to pass through malarial districts. 



TYPHOID FEVER. 



The microbe of this disease has been found in 

 Peyer's glands, the spleen, larynx, lungs, liver, and 



1 Mr. C. T. Kingzett, F.C.S., manufactures these substances 

 on a large scale. He decomposes the essential oils (principally 

 turpentine oil), in the presence of water, by passing a current 

 of air into them, the products being sold as ' Sanitas ' fluid and 

 oil, both of which are powerful germicides. Kingzett imitates 

 the decomposition of the essential oils by a similar process as 

 the one which goes on naturally in the eucalyptus, pine, and 

 camphor forests. It may be stated that 0'4 gramme of ' Sani- 

 tas' oil completely destroyed Micrococcus prodigiosus, Bac- 

 terium allii, Bacillus tuberculosis, and Bacillus subtilis when 

 grown in various media as tube-cultivations. 



" Atti della R. Accademia del Lincei, 1885. 



