January 6, 1872.1 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
515 
still remains (three months after), without mould or 
taint. One ounce of ox muscle was immersed for twenty- 
hours in four ounces of an aqueous solution of carbolic 
acid (1-1000), then suspended in air. In six days it was 
much hardened, brownish-black, speckled with mould, 
and distinctly tainted. 
It appears that chromic acid acts as an antiseptic by 
coagulating- protean compounds, a property which it pos¬ 
sesses in the highest degree, and to which I am not aware 
that attention has been hitherto directed, although used 
for a considerable time in hardening animal tissues for 
microscopical examination. The coagulating power of 
chromic acid in albuminous solutions has been compared 
with that of most metallic salts, various acids, etc., and 
found to exceed them all: e. g. it has about ten times the 
coagulating power of carbolic acid, fifteen times that of 
nitric acid, twenty times that of bichloride of mercury, 
and a hundred and fifty times that of chlor-alum, etc. 
Shortly after a piece of muscle is immersed in a solution 
of chromic acid, there forms in considerable quantity a 
greyish, opaque, granular sediment, coagulated albumen ; 
while the deep red of the muscle is changed to brownish- 
yellow, ultimately it looks as if it had been boiled, the 
residual portion of muscle being composed almost exclu¬ 
sively of fibrous stroma, and becoming, on drying, ex¬ 
tremely hard and tough. A portion of muscle immersed 
in a solution of carbolic acid retains a light pinkish, 
somewhat blanched aspect; while the solution, remain¬ 
ing- void of sediment, is reddish and hazy, but translu¬ 
cent. If to a portion of this fluid there be added a little 
chromic acid solution, not stronger than 1-1000, a volu¬ 
minous precipitate of albumen is at once obtained, clearly 
demonstrating the superior coagulating power of chromic 
acid over that of carbolic acid. 
A solution of two grains per ounce at once indicates 
the presence of albumen in a solution consisting of one 
part of a saturated solution of beef juice in twenty of 
water; while one of beef juice in thirty of water may 
be detected by allowing the mixture to stand for twelve 
hours. Chromic acid is admirably adapted for deter¬ 
mining volumetrically the percentage of albumen in a 
fluid. An albumenometer may be constructed as follows : 
Fill a wide-mouthed burette to a multiple of 100 with 
albuminous urine or an albuminous fluid; add solution 
of chromic acid, about four grains per ounce, in slight 
excess; shake the mixture; set aside for twenty-four 
hours; read off the precipitate, and multiply to per cent. 
No heating is required. Chromic acid also coagulates 
mucus, saliva, chondrin, and gelatine. With the latter 
two it forms, in excess, canary-yellow fluids and floccu- 
lent precipitates coloured like chromate of lead. The 
reaction with gelatine is as delicate as that with tannin, 
giving a response with 1 to 5000. Chromic acid is 
therefore a test for gelatine. An aqueous solution of 
carbolic acid (1 to 20) produces only slight haziness in 
gelatinous solutions. 
Disinfecting properties. — Chromic acid coagulates, 
hardens, and oxidizes decomposing organic matter. It 
combines simultaneously with ammoniacal products and 
with nascent sulphuretted hydrogen, reducing the latter 
to water and free sulphur (2Cr0 3 x 3H 2 S = Cr 2 0 3 
x 3H 2 0 + 3S). Added to putrid blood, flesh, pus, urine, 
or fiecal matter, the offensive odour is soon absolutely 
removed, the mixture remaining fresh for an indefinite 
time. Dr. R. A. Smith found that bichromate of potas¬ 
sium surpassed thirteen other of the most energetic an¬ 
tiseptics, including carbolic acid, in preventing the evo¬ 
lution of sulphuretted hydrogen in a mixture of equal 
parts of blood and water.* This salt has a coagulating 
power near that of nitric acid ; i. e. fifteen times weaker 
than that of chromic acid. Hoppe Seyler has shown 
that, “while in disinfection it is highly necessary to de¬ 
stroy the products of fermentation and putrefaction, yet 
the destruction of sulphuretted hydrogen and ammonia 
* ‘Disinfectants and Disinfection/ pp. 89, 91. 
can have no more influence on the fermentative changes 
involved in cholera and typhus than the removal of car¬ 
bonic acid can have upon the progress of alcoholic fer¬ 
mentation ; and therefore the ferment itself must be 
attacked, which, as pointed out, is more resistent than 
the living organisms in decomposing solutions.”* Now- 
chromic acid, as already shown, fulfils admirably these 
requirements. Carbolic acid does not combine with am¬ 
monia, nor decompose sulphuretted hydrogen. This is 
surely of importance in a sanitary sense, when it i3 re¬ 
membered that almost to these properties alone are due 
the marked disinfecting powers of sulphurous acid, ni¬ 
trous acid, permanganate of potassium, bisulphite of 
lime, protosulphate of iron, chloride of zinc, chloride of 
aluminium, chlorine, bromine, iodine, etc. Carbolic acid 
seems to act as an antiseptic solely by coagulating albu¬ 
men. It does not preserve by absorbing and retaining- 
moisture, like chloride of sodium, alcohol, etc., as, prac¬ 
tically, it has no affinity for water. Chromic acid is tho 
reverse. 
In Dr. A. E. Sansom’s book, page 28,f the following 
passage occurs:—“It has been shown, however, that 
carbolic acid has the faculty of coagulating albumen. Is 
it on account of this faculty that it prevents fermenta¬ 
tion and putrefaction ? On this point a comparative ex¬ 
periment throws some light. Let a solution of the albu¬ 
men of egg be precipitated, in one case by heat or by an 
ordinary chemical reagent, and in the other by a solution 
of carbolic acid, and let the resultant precipitate be kept 
a considerable time in contact with the air. It will be 
observed that whereas in the one case the albumen will 
become decomposed in the ordinary manner, that preci¬ 
pitated by the carbolic acid entirely resists putrefactive 
change. It is therefore obvious that carbolic acid has 
an action over and above its action as a mere precipitant 
of albumen.” The fact is here ignored that in general 
chemical precipitates of albumen are soluble in water, 
specially carbolico-albuminoid precipitates; and as the 
latter cannot exist without the presence of carbolic acid, 
the difference between the “carbolic” and “heat” pre¬ 
cipitates is simply that the one contains an antiseptic, 
while the other does not. As regards the other precipi¬ 
tates, the alleged results only show that carbolic acid is 
a more powerful antiseptic than any of the ordinary 
chemical reagents referred to. Furthermore, it may be 
urged that carbolic acid is volatile, whereas chromic 
acid is fixed ; therefore the former can arrest putrefaction 
by coagulating floating particles of organic debris. But 
in a series of experiments by Dr. R. A. Smith, j “ to de¬ 
termine the efficiency of strong gases and volatile sub¬ 
stances in preventing putrefaction,” it is shown that 
pieces of fresh meat suspended in bottles containing 
chlorine, bromine, iodine, hydrochloric acid, ammonia, 
protoxide of nitrogen, nitrous acid, and sulphurous acid, 
were fresh at the end of twenty-eight days; while a 
piece suspended in a bottle containing heavy oil of tar, 
and a piece in a bottle containing M'Dougall’s powder, 
of which the chief ingredient is crude carbolic acid, grew 
slimy and putrid in seven days. I have also made the 
following experiment:—A piece of ox muscle, a portion 
of beef j uice, of urine, and of infusion of hay, the three 
latter in separate phials, were suspended in a gallon 
bottle, which contained fully a pound of pure carbolic 
acid, about six inches from its surface. Tho bottle was 
kept open at about 60° F. On the fourth day tho beef 
juice was putrid and swarming -with bacteria, vibriones, 
etc. A portion of the same juice exposed to the air was 
not more putrid on the fourth day than that in the bottle. 
On the fifth day both the mine and infusion of hay 
teemed with life; while on the surface of the latter thera 
was an abundant development of penicillium. On the 
sixth day the piece of muscle was putrid and slimy. 
* The Lancet, Aug. 26th, 1871. 
f The ‘Antiseptic System’. By A. E. Sansom, M.D. Load. 
x ‘ Disinfectants and Disinfection/ p. 109. 
