August 20, 1870.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
143 
It is well known that pure colourless blood se¬ 
rum, of the same degree of concentration as in blood, 
may be left for weeks in contact with the air, and 
that it will not putrefy; while defibrinated blood, on 
the mixture of blood serum with the corpuscles of 
the blood, rapidly passes into a state of putrid fer¬ 
mentation. In tliis case the blood-pigment appears 
to act upon the albumen of the blood just in the 
same way as yeast acts on sugar. An addition of a 
thousandth part of prussic acid to blood is sufficient 
to suppress putrefaction for a long time, just the 
same as it prevents the fermentation of sugar. 
Neither strychnine, quinine, pyrogallic acid, nor 
oxide of mercury prevents the action of blood-pigment 
upon peroxide of hydrogen, neither does chloroform 
nor hydrate of chloral. Blood diluted with water is 
rendered sensibly paler-coloured by chloroform, 
while, on the contrary, the colour is darkened by 
hydrate of chloral, even in a slightly acid solution. 
Thenard observed that well-washed white blood 
fibrine, when mixed with peroxide of hydrogen, pro¬ 
duces the same effect as Schonbein observed with 
blood-pigment; the threads of fibrine immersed in a 
solution of the peroxide become covered with gas 
bubbles. However, if the fibrine be moistened be¬ 
forehand with a few drops of prussic acid, and left 
for an hour before being immersed in the solution of 
peroxide, there is then no evolution of gas caused. 
In the behaviour of yeast-cells towards chemical 
■agents, such as strychnine, chloroform, quinine, and 
prussic acid, there seems to be some analogy with 
the influence exercised by some medicines upon cer¬ 
tain parts of the living animal body, and from this 
point of view it may be of interest. 
In regard to yeast as a plant-cell, it is remarkable 
enough that it has a chemical composition nearly 
the same as that of animal structures; the chief dif¬ 
ference is, that the cell-membrane of the yeast-cell 
consists of a non-nitrogenous material. The mineral 
constituents are the same in both cases, and in the 
large amount of potash and phosphoric acid present 
analogy with those of muscle; moreover, the pro¬ 
ducts of the putrefaction of yeast-cells are scarcely 
different from those afforded by animal materials. 
It is to be assumed that in the living cell in the 
animal organism, there is incessant transformation 
or metamorphosis just as in yeast-cell; also, that 
the action of many medicines upon the living body, 
such as quinine, chloroform, prussic acid, etc., de¬ 
pends essentially upon the influence exercised by 
them upon the normal state of metamorphosis upon 
their altering the condition and normal functions of 
the nerves. Some chemical agents, such as sulphu¬ 
retted hydrogen and pyrogallic acicl, act in a purely 
chemical manner upon the blood; but the action of 
quinine, of prussic acid, or of strychnine is not so 
simple, and it does not admit of explanation simply 
by chemical alterations. 
The liver and some glands may be compared to a 
system of yeast-cells in which, during its construc¬ 
tion out of the constituents of the blood, peculiar 
compounds are formed that constitute the contents 
of the cells—compounds that have only a temporary 
existence, that exercise a special action upon the 
blood and its constituents (inasmuch as their consti¬ 
tuents separate or arrange themselves differently)— 
just as the yeast-cells act uponbeer-wort, and while de¬ 
composing its sugar, constantly reproduce themselves. 
The observation recently made by Sclimulewitsch, 
under the guidance of Ludwig, that the liver of 
a freshly-killed rabbit continues to secrete bile for 
several lioms when defibrinated dog’s blood is passed 
through it, is, in this respect, of the greatest signi¬ 
ficance, and so is the formation of sugar in the liver 
observed by Bernard to take place even when the 
food consists exclusively of flesh. 
The fact that a fresh calf’s liver cut into pieces, 
and kept in water at 30° to 40° C., begins after four 
or six hours to evolve pure hydrogen gas without 
giving off the slightest smell, is, I believe, indicative 
of a powerful process of metamorphosis going on in 
the liver. Considering the part played in digestion 
by one of the organic substances contained in the 
gastric secretion ; considering also the peculiarities of 
the saliva and of the pancreatic secretion, it is 
scarcely possible to avoid the conclusion that a 
number of processes in the animal organism are de¬ 
pendent on the same causes that give yeast its 
remarkable influence. 
ON MEDICINAL PEPSIN.* 
BY RICHARD V. TUSOX, F.C.S., 
Professor of Chemistry at the Royal Veterinary College. 
Since the introduction into medicine of Corvisart and 
Boudault’s “poudre nutrimentive ” in the year 1854, 
pepsin obtained from the stomach of the pig,f calf, or 
sheep, in a state of greater or less impurity, has been 
extensively prescribed in dyspepsia and certain other 
affections. According to the testimony of some autho¬ 
rities of high standing, long experience in the use of this 
agent fully justifies the predictions relative to its thera¬ 
peutic value, which were put forward by Corvisart as based 
upon physiological reasoning. However, there are other 
authorities, equally eminent, who either express doubts as 
to the efficacy of pepsin, or positively state that it is 
totally devoid of medicinal power. In all probability 
this difference of opinion mainly arises from the cir¬ 
cumstance that pharmaceutists supply medical men with 
various preparations ; all hearing the same specific name 
of pepsin, but differing very considerably in their di¬ 
gestive powers and other qualities. In fact, so far as 
I have at present been able to collect evidence rela¬ 
tive to the merits and demerits of pepsin, I find those 
who speak favourably of its employment in the treat¬ 
ment of disease have prescribed that prepared by the 
best makers; while those who express a doubtful or ad¬ 
verse opinion respecting its value have been in the habit 
of prescribing those varieties or makes which the expe¬ 
riments of myself and others have proved to be practi¬ 
cally without any digestive activity whatever. The 
relative digesting capability of several samples of English 
and Continental pepsin was investigated by Dr. Sieve- 
king;]; in 1857 and a similar inquiry was conducted by Dr. 
Pavy§ in 1863. The results of the experiments of both 
gentlemen indicated that there was not merely a differ¬ 
ence in the qualities of the pepsin prepared by different 
makers, but that—as was particularly shown by Dr. 
Ravy—some of the samples examined were totally incap¬ 
able of digesting muscular tissue. One would, have 
thought that the publicity given to these facts in the 
medical journals would have caused the prescription of 
none but the best makes of pepsin; that it would, also 
have induced those who had hitherto fabricated an infe - 
rior article either to have abandoned its manufacture, or 
to have improved the methods they employed for its 
preparation. Such, however, was not the case, for phar¬ 
maceutists at the present date continue to vend, while 
* From the 1 Lancet,’ August 13,1870. 
•f First brought into notice by Dr. Beale. 
‘ Medical Times and Gazette,’ 1857, vol. i. p« 336. 
The ‘ Lancet,’ April 25th, 1863. 
