204 ACTION OF COAL-TAR PRODUCTS, 
Huphorin (Phenylurethan) has been tested by Colasanti (1894), 
who finds that it has rather feeble germicidal activity. 
Formaldehyde (formol, formalin) has very decided germicidal 
power. According to Pottevin (1894) in the absence of spores a solu- 
tion of 1:1,000 kills bacteria, in comparatively small numbers, in from 
fifteen minutes to several hours. For the destruction of spores a 
much strorger solution is required—a fifteen-per-cent sciution at 
15° C. killed anthrax spores in one and one-half hours, and spores 
of Bacillus subtilis in twenty hours. At higher temperatures the 
germicidal action is more energetic, and microérganisms exposed to 
the vapor of formol are very quickly destroyed. Vanderlinden and 
de Buck (1895) find that solutions of formalin are decidedly inferior 
to corresponding solutions of carbolic acid, creolin, or solvéol, and are 
too irritating to be used in surgical practice. They report that a 
solution of five per cent failed to destroy their test organisms— 
Bacillus coli communis, Bacillus typhi abdominalis, Staphylococcus 
pyogenes aureus. Experiments made by Reed, at the Army Medical 
Museum in Washington, show that the diphtheria bacillus and other 
test organisms are quickly killed by formalin vapor. 
Glycerin has no action upon the virus of symptomatic anthrax 
(Arloing, Cornevin, and Thomas), and is inert as regards the spores 
of anthrax (Koch). Glycerin prevents putrefactive decomposition in 
bouillon when present in the proportion of 1:4 (Miquel). Roux has 
shown that the addition of five per cent of glycerin to a culture 
medium is favorable to the growth of the tubercle bacillus; it is also 
appropriated as pabulum by various other species. 
Guatacol.—Kuprianow, as a result of extended experiments with 
this agent (1894), reports that it ranks below cresol and carbolic acid 
asa germicide. In the proportion of 1:500 it restrains the develop- 
ment of the cholera spirillum, and the author named suggests its in- 
ternal administration in this disease on account of its non-toxic and 
non-irritant properties. 
Hydroxylanin.—Heinisch found that the development of the 
anthrax bacillus is prevented by 1:77 of hydroxylamin hydro- 
chlorate, and of the diphtheria bacillus by 1:75. In these experiments 
a solution of soda was added to release the hydroxylamin. Marp- 
mann found that 1:100 preserved milk without change for four 
to six weeks, and that alkaline fermentation of urine was prevented 
by 1:1,000. 
Ichthyol.—Latteux (1892) reports that the various pathogenic 
bacteria used by him as test organisms were killed by a five-per-cent 
solution (time ?) with exception of Streptococcus pyogenes, which 
required a six to seven-per-cent solution. The more recent experi- 
ments of Abel (1893) gave less favorable result, but the agent was 
