March 1, IS:3.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTION" 1 
685 
and appears to be principally used in medicine. It 
is called jungle-geerah oil in Mysore. The oil ob- 
tained from the same source in Egypt is limpid and 
colourless, and with but little odour. A specimen 
from Egypt, with the seeds, was shown at the first 
London Exhibition in 1851. 
The seed is called gitta by the Arabs. Lady 
Calcott, in her ‘ Scripture Herbal,’ states that the 
seed is much esteemed in the East, where it is com¬ 
mon to strew it over the floor of the oven before the 
bread is put in, and to sprinkle it over the loaves, and 
even to knead it into the dough, as is done with 
poppy seeds in Bohemia and some parts of Germany. 
The seed of the Nigella is used in this manner and 
also by way of pepper in Egypt, Persia and India, 
as well as in Syria and Palestine, and very powerful 
as well as healthful qualities are ascribed to it. 
Under the strange name of fennel-flower, this plant 
was formerly cultivated in our gardens as a pot-herb, 
but like many others it has been displaced by the 
more common and pungent Eastern spices. 
CONTRIBUTIONS TO THE PHYSIOLOGICAL CHE¬ 
MISTRY OF MILS.* 
BY P. SOXHLET. 
Soxhlet investigates the question as to the identity of 
casein and alkali-albuminate, concerning which there 
exist considerable differences of opinion. 
Ho first discusses the relation of alkaline phosphates 
to alkali-albuminate. 
Hoppe-Seyler opposes the identity of casein and alkali- 
albuminate on the ground that in the milk no alkali- 
albuminate can be present, inasmuch as the fluid gene¬ 
rally has an acid reaction, whereas solutions of the latter 
substance arc precipitated even on neutralisation, 
llollett, however, has proved that solutions of alkali- 
albuminate are not precipitated by acids in presence of 
neutral sodium phosphate, and it is owing to the presence 
of such phosphates in the milk that casein, which be¬ 
haves exactly like alkali-albuminate, is not precipitated, 
even though the milk exhibits an acid reaction. Follow¬ 
ing out Rollett’s researches, Soxhlet seeks to determine 
the quantitative relation of the acids and salts in the 
liquids in which, notwithstanding an acid' reaction, no 
precipitation of albuminate occurs. By experiments 
with volumetric solutions of neutral sodium phosphate, 
acid potassium phosphate, neutral sodium sulphate, sul¬ 
phuric, acetic and phosphoric acids, he arrives at the 
result, that on the addition of an acid to a solution of 
alkali-albuminate in presence of neutral sodium phos¬ 
phate, the albuminate begins to be precipitated at the 
moment when all the neutral phosphate has been con¬ 
verted into the acid salt. The quantity of acid required 
for precipitation stands in intimate relation to the quan¬ 
tity of alkaline phosphate present, and tho precipitation 
depends, not on the absolute amount of acid phosphate 
formed, but on its relative proportion to the neutral 
phosphate still remaining. The sodium sulphate which 
is formed when sulphuric acid is added to the albuminate 
solutions in neutral sodium phosphate, is without in¬ 
fluence on the precipitation of the albuminate. 
A relatively small amount of acid phosphate causes 
precipitation in pure alkali-albumin ate solutions. In 
order to cause precipitation when neutral phosphate is 
present, a much larger proportion of the acid salt is re¬ 
quired, because if the former is in excess, the albuminate 
remains in solution. In order to cause precipitation, it 
was found that acid phosphate of alkali-metal must be 
added until the quantity of neutral phosphate, which is 
* Journ. f. pract. Chemie. [2], vi., 1— 52; and from the 
f Journal of the Chemical Society.’ 
formed from the base of the alkali-albuminate and from 
a part of the acid phosphate, stands in tho relation of 
one molecule to thirty-two molecules of the acid phos¬ 
phate. If more neutral phosphate is present than is ex¬ 
pressed by this proportion, no precipitation occurs. 
Reaction of the Milk and other Animal Fluids .—Tho 
solution of casein in milk with an acid reaction must, as 
shown by the foregoing experiments, depend on the 
simultaneous presence of a certain proportion of neutral 
.phosphate together with the acid phosphate which gives 
the acid reaction. Such solutions, however exhibit not 
merely an acid but also an alkaline reaction at the same 
time. And this is really the case with the milk, for it at 
the same time reddens blue litmus and turns red litmus- 
paper blue. This amphoteric reaction of milk can bo 
demonstrated best on gypsum plates coated with litmus, 
after the manner suggested by Liebreich. To this 
amphoteric reaction of the milk, the author ascribes the 
different statements made in regard to the normal re¬ 
action of the fluid. The alkaline reaction becomes more 
evident when the milk is heated. The same is shown 
by very dilute solutions of so-called neutral sodium 
phosphate and caustic soda. Violet solutions of litmus 
also become more blue on heating. The change is not 
due to concentration by evaporation, as the original 
colour reaction returns on cooling. Fluids which con¬ 
tain vegetable albumen become more alkaline when 
heated, and it has been supposed that this is due to the 
liberation of an alkali when tho albumen is coagulated. 
That it is not due to this cause is proved by the fact that 
solutions free from albumen, but containing the same 
salts as the albuminous liquids, likewise exhibit the same 
intensification of the alkaline reaction when heated. A 
similar explanation is given of the fact observed by Du 
Bois Reymond, that a muscle dipped in boiling water 
becomes more alkaline than before. 
In connection with the amphoteric reaction of animal 
fluids, difficulties are pointed out in the estimation of the 
so-called free acid of the urine. The presence of acid 
sodium phosphate in the urine renders it difficult to say 
exactly when all the acid is neutralised by the addition 
of alkali, because it is impossible to hit a point when tho 
liquid will react exactly neutral, as there is no solution 
of a phosphate which reacts precisely neutral. 
A third objection to the identity of casein and alkali- 
albuminate is supposed to exist in the different behaviour 
of these two substances towards rennet. Milk is coagu¬ 
lated, while alkali-albuminate is not. It has been 
shown, however, that alkali-albuminate is coagulated by 
rennet when milk sugar has been added to the solutior. 
Soxhlet agrees with Simon in referring the coagulation 
to the lactic acid developed by the action of rennet on 
milk-sugar. Heintz, however, and subsequently Volcker 
found that casein might be coagulated by rennet, and 
vet the fluid remain alkaline, and. hence considered that 
rennet |may coagulate casein, not only by the formation 
of lactic acid, but also by some specific action. For this 
specific action a higher temperature is necessary. 
Soxhlet explains tho differences by the amphoteric reac¬ 
tion. Rennet develops lactic acid from tho milk-sugar; 
by which the neutral alkaline phosphate of the milk is 
converted into acid phosphate. When in consequence 
of this acidification, that relation between the neutral 
and acid phosphate is established in which the albumi¬ 
nate remains just dissolved and no more, then when the 
temperature is raised albumen is precipitated while the 
fluid is still alkaline. Along with the alkaline reaction, 
however, an acid reaction is also to be observed. This, 
however, had not been noticed by former observers. 
The statement that the casein precipitated by acid L 
easily soluble in sodium carbonate, while that precipi¬ 
tated by rennet is not so, depends merely on the .physical,, 
and not on any chemical differences of the precipitate. 
Rennet belongs most probably to the non-organised 
ferments. Zalin states that alkali-albuminate may bo 
filtered through porous earthenware, but casein not; and 
