146 

point as butter, and he is able, further, to vary 
the melting point to suit the climate, an advantage 
which will be more fully appreciated in the 
future when margarine has found its way to 
tropical countries. 
The present success of the margarine manu- 
facturer is to a large extent due to the great 
variety of raw materials which are now available. 
In the early days of the industry soft beef fat 
was the sole basis obtainable; this was known 
as oleo oil or oleomargarine, and the conditions 
of its manufacture were not always above 
suspicion. This has now been entirely changed; 
the factories are models of cleanliness; they are 
officially inspected, and above all, animal fats have 
become of secondary importance to vegetable oils. 
The process of manufacture is briefly as 
follows :—The carefully purified oils are blended 
at a suitable temperature, churned and pulverised 
with new or separated milk in suitable machines, 
cooled, washed, salted if required, and worked 
in exactly the same way as butter. The product 
is a butter substitute, and has the same com- 
position, viz., about 84 per cent. of fat. There- 
fore on the accepted standards it has the same 
nutritive value. 
A certain amount of butter fat is usually con- 
tained in the mixture, but by law this is not 
allowed to exceed 10 per cent. In Germany, 
Austria, and Denmark the presence of 10 per cent. 
of Sesame oil is obligatory for the purpose of ear- 
marking the substitute. Sesame oil gives a 
colour reaction with certain reagents, which 
enables its presence to be very readily detected; 
for the British palate this addition of Sesame oil 
is unwelcome. In Belgium the addition of o 2 
per cent. of potato starch, as well as of 5 per cent. 
of Sesame oil to margarine is obligatory. It may 
be remarked that the analytical discrimination 
between butter and margarine is a lengthy process, 
and that the detection of 10 or 15 per cent. of 
added fat to butter is a matter of considerable 
difficulty. All fats are very much of the same 
composition, and with one or two exceptions they 
lack individual characteristics. The analyst 
depends, therefore, on small differences in physical 
characteristics, or on the proportion of fatty acids 
of low molecular weight, for their identification 
when in admixture. 
It is an increasing practice in factories and for 
culinary operations in restaurants or in the kitchen 
to use the pure or blended fats themselves without 
churning them with milk. The advantages of this 
procedure are obvious, and it will be followed more 
generally by the housewife in the future. Thus 
in the United States, and in the poorer districts 
of our large towns, enormous quantities of refined 
cotton seed oil are sold for frying purposes, and 
the use of nut and blended butters containing 100 
per cent. of fat for the same purpose is largely on 
the increase amongst the upper classes. 
With the exception of olive oil the edible vege- 
table oils require very special refining before their 
characteristic flavours or impurities can be re- 
NOM2371; VOL. Osi 
NATURE 


[Aprit 8, 1915 
moved; in consequence it is only since these diffi- 
culties have been overcome in practice that they 
have been so largely used for margarine. It is 
certain that as the knowledge of refining processes 
increases, the development of the industry will 
be still greater. The methods of refining vary 
according to the oil; they are mostly jealously 
guarded as valuable secrets. 
In Britain, and particularly in the United States, 
very large quantities of cotton seed oil are used 
either in margarine or for culinary purposes, both 
as a substitute for olive oil and as a cooking fat. 
About three-fourths of the world’s production 
comes from the United States, about half of this 
oil being refined for edible purposes. The crude 
oil obtained by pressing the seed is first treated 
with caustic soda, then with fuller’s earth, and 
finally made as nearly as possible free from taste 
and odour. From the point of view of the mar- 
garine maker, cotton seed oil is too liquid to be 
used.in any large proportion, though its relatively 
low cost makes it a very desirable ingredient. 
Far more important as butter substitutes are 
the nut oils—coco-nut, and palm kernel. The 
former is obtained by pressing copra—the flesh of 
the coco-nut, which is exported in a dried con- 
dition from its place of origin. In the past the 
copra-pressing industry has been localised at 
Marseilles, though in later years an almost equal 
quantity of material has been dealt with at Ham- 
burg. 
Palm kernels are the seeds of the palm fruit, of 
which the fleshy part is utilised for the manu- 
facture of palm oil. The natives on the West 
Coast of Africa collect the kernels, crack and 
remove the shell before the nuts are exported to 
Europe. It is stated that kernels were first 
brought to Marseilles as ships’ ballast and thrown 
into the sea on arrival until their value was recog- 
nised. Originally the chief receiving port was 
Marseilles, but latterly the industry has been 
almost entirely carried on at Hamburg, where in 
IQII 93 per cent. of the total quantity was dealt 
with, the remainder going to Liverpool. 
The palm kernel oil made in North Europe last 
year is estimated at 125,000 tons, of which about 
40,000 was refined for edible purposes. The 
kernels contain about 50 per cent. of oil, which 
is extracted by pressing in hydraulic presses 
similar to those used for copra. The residue, 
palm kernel cake or meal, has found a very wide 
use in Germany as an ingredient of compound 
cake for cattle feeding, and in this form has been 
largely exported to England. The commercial 
success of the pressing industry largely depends 
on the price obtained for this meal, and no pains 
have been spared on the Continent to demonstrate 
its value to the farmers by means of scientifically 
conducted feeding trials. There is at present 
much talk of developing the industry in Britain, 
in which case the disposal of the cake here will 
be an important consideration. It is of interest 
that the decline of the industry in Marseilles is 
largely due to the cake failing to find a ready sale 
