The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1898-02-26

| imperfect washing of the vessels used 10
| contain the m ore highly arsenicai colors,
and states that dyed and printed fabrics
| onw very frequently contain traces of ar
| senic. He recommends the use Of preci-
plated borate OF copper as a green pig
! ment 70 replace arsenical greens as long
| ago proposed by Boney. In view of the
present low price of boric acid. this pig
ment ould be used commerciany.-
! Science.
! DISINFECTANTS' RELATIVE VALUE.
There are a number of disinfectants on
| the market of more or less value says
writer in the Paint. Oil and Drug Review,
| and it is the object of this paper TO give
the dealer and consumer some method of
| determining the relative value of these
various products. Infections are caused
by various kinds of bacteria, but all these
bacteria do not hrive under the same con-
ditions A substance may form an excel
lent medium for the growth of one kind
of bacteria, while it may be positively
fatal to other kinds. So in determining
the value of a disinfectant, it is necessary
to determine its effect upon specific forms
Of bacteria. Although the chemical consti
tuition and strength of disinfectant can
be determined by chemical means. 1T is
necessary to resort to a archaeological
examination in order to be certain of its
value as a disinfectant. A archaeological
examination may be conducted as fol-
lows:
a series of test tubes are filed with So
lutions of disinfectants of different de-
grees of strength, and in each of them is
placed a silk thread impregnated with
some specific form of bacteria (e. s..
bacterium cold. At the end of definite in
tervals of time the threads art removed.
washed with sterilized water and placed
in a culture medium of gelatin or agar.
The culture tubes containing the culture
medium. are then placed in a sterilized
chamber until the bacteria shall have had
time to develop. If the solutions are
strong enough, and If sufficient time be
allowed for the action of the dsnfectants,
no colonies of bacteria will be found, but
if on the other hand, the solutions were
too weak, or if the time for the action of
the disinfectant be too short, numerous
colonies of bacteria will be found. In
every case IL will be found that in a GER
tain strength of solution the bacteria will
thrive while in a somewhat stronger So
luton they will be killed. Thus, a solu-
ton of one part of thymol in 1900 of water
will prevent alcoholic fermentation, but If
the solution be diluted to one in $500 the
fermentation will proceed. A solution of
one part salicplic acid in 1000 parts of wa
ter will prevent fermentation, but If di-
luted to one in l 200 fermentation will take
place. A solution of one part thymol in
1900 of water is the weakest solution of
that antiseptic that will prevent fermen-
tation, while a solution of one part Of
salicyIic acid in LOCO of water is the equi-
valent strength of that solution for hinder
ing fermentation. Therefore, IL may be
said, that thymol has three times the dis
injecting power of salicylic acid. In a
similar way all antiseptics may be COM
pared. The following table gives the min
imum strength of some well known anti
septics that will prevent alcoholic fer
mentation. The figures show the weakest
concentration to prevent fermentation:
Corrosive sublimate 10000
Potassium permanganate.... ........L 10000
Copper sulphate (blue vitrioD. ......L40OO
Bromin..-.. ....---....l3ooO
Thymol..... ......... .-.....l3009
BenZotc acid....... ...... .......l200O
Salcplic acid ...... -. recommendation
Qulnlne ............. ....' -. .......--..l4D
Carbolic acid........ -. 80. ........L200
Sulphuric acid. .-.... .............ll00
ResOrcin ........... .-..... .........llo0
Pyrogallol .......-........ .-...-......l5D
z. oric acid. $500. .............l25
Choral hydrate e. 80. ...............I25
Daily Eagle by carrier. 10 cents per week. |