SCIENCE. 
75 
SCIENCE AT BREAKFAST. 
By The Editor. 
The sterling goodness of Dr. Johnson’s heart, not- 
withstanding many apparently blunt demonstrations to 
the contrary, was never more clearly demonstrated, than 
when he remarked to Boswell, “ I encourage this house, 
for the mistress of it is a good civil woman, and has not 
much business.” 
The house referred to was the “ Turk’s Head Coffee 
House.” But coffee houses, nay coffee drinkers, have 
much changed in outward form since the days of the 
sturdy old philosopher. The beau and the belle no 
longer, in picturesque costumes, discourse scandal, sip- 
ping the Eastern beverage from exquisite specimens of 
china ware, and tea and coffee, no longer a luxury, are 
now enjoyed by the toiling millions, and esteemed a 
blessing by all classes. 
Although tea and coffee is universally used by the civ- 
ilized nations of the world, few understand the natural po- 
tent properties of these substances, or are even conscious 
of their powerful action upon the human system, and as 
it is a subject interesting to so many, I offer the following 
sketch, treating of the more important points. 
Coffee, tea and chocolate all contain in common a ni- 
trogenised basis, to which they owe most of their impor- 
tant chemical properties. Tea and coffee even contain 
the self-same basis, denominated indiscriminately theine 
or caffeine. In chocolate the cocoa principle called theo- 
bromine is richer in nitrogen than the theine. 
The chemical constituents of these substances are as 
follows : While in tea the basis is combined with tannic 
acid, in coffee it forms a salt, with a peculiar tannic acid, 
containing a greater proportion of nitrogen, which to- 
gether with tannio-caffeic acid is united with potash 
into a so-called double salt. Tanno-caffeic acid when 
roasted, develops the agreeable odor of coffee. 
Not only the same basis, but also two similar organic 
acids, one contained in tea, the other in coffee, increase 
the conformity, between the leaves of the former and the 
beans of the latter. 
Legumin, cellulose, gum, sugar, citric acid in addition 
to oleine, and what is called palm-fat, accompany the or- 
ganic acids and the theine of the coffee beans. 
But the tea leaves, apart from the basis and the acids, 
are composed of albumen, cellulose, gum and wax, the 
green pigment of the plant and the volatile oil of tea 
This peculiar oil is the principal source of the aroma 
of tea, by which, in spite of the conformity between tea 
and coffee, it essentially differs from the latter. 
The inorganic constituents of tea and coffee are more- 
over different. While in coffee, chlorine, phosphoric and 
sulphuric acids are combined with potash, lime, magnesia 
and oxide of iron ; tea contains another inorganic acid 
besides, consisting of manganese and a large proportion 
of oxygen. 
So much for the chemical constituents of coffee and 
tea. Let us now examine their peculiar properties and 
nutritive qualities. 
Chocolate from its large proportion ot albumen is the 
most nutritive beverage, but at the same time from its 
quantity of fat, the most difficult to digest. But its aro- 
matic substances strengthen the digestion. A cup of 
chocolate is.an excellent restorative and invigorating re- 
freshment even for weak persons, provided their diges- 
tive organs are not too delicate. Cardinal Richelieu 
attributed to chocolate his health and hilarity during his 
later years. 
Tea and coffee do not afford this advantage. Albu- 
men in tea leaves, and legumin in coffee berries, are 
represented in very scanty proportions, for while in the 
former the albumin is coagulated by boiling water, in the 
latter the legumin is prevented from being dissolved by 
the lime with which it is combined. 
The praise of tea and coffee as nutritive substances is, 
therefore, hardly warranted, because, as restoratives for 
the body, the alimentary principles and not the elements 
are to be taken into account. The former principle cannot 
be ascribed to “ Theine,” which is excreted again as urea 
with surprising rapidity, and to this swift transformation 
tea and coffee owe their diuretic action, which is consid- 
erably assisted by the warm water of the infusion. 
Tea and coffee, though of themselves not difficult of 
digestion, tend to disturb the digestion of albuminous 
substances by precipitating them from their dissolved 
state. Milk, therefore, if mixed with tea or coffee, is 
more difficult of digestion than if taken alone, and coffee 
alone without cream promotes digestion after dinner by 
increasing the secretion of the dissolving juices. 
The volatile oil of coffee and the empyreumatic and 
aromatic matters of chocolate accelerate the circulation, 
which, on the other hand, is calmed by tea. 
Tea and coffee both excite the activity of the brain and 
nerves. 
Tea, it is said, increases the power of digesting the 
impress'ons we have received, creates a thorough medi- 
tation, and, in spite of the movements of thoughts, per- 
mits the attention to be easily fixed upon a certain sub- 
ject ; a sense of cheerfulness and comfort ensues, the 
functions of the brain are set in motion, the thoughts are 
concentrated and not apt to degenerate into desulto- 
riness. 
On the other hand, if tea is taken in excess, it causes 
an increased irritability of the nerves, characterized by 
sleeplessness, with a general feeling of restlessness and 
trembling of the limbs ; spasmodic attacks may arise, 
with difficulty of inspiration in the cardiac region. The 
volatile oil of tea produces heaviness in the head, first 
manifesting itself in dizziness and finally in stupefaction. 
These symptoms have been called an evidence of a 
real tea intoxication. Green tea, which contains much 
more of the volatile oil than the black, produces these 
obnoxious effects in a far higher degree than the latter. 
While tea principally revives the faculty of judgment, 
and adds to this activity a sensation of cheerfulness, 
coffee acts also on the reasoning faculties, but without 
communicating to the imagination a much higher degree 
of liveliness. 
Susceptibility to sensuous impressions is intensified by 
coffee ; the faculty of observation is therefore increased, 
while that of judgment is sharpened, and the perceptions 
adopt more quickly certain forms, activity of thoughts 
and ideas is manifested, a mobility and ardor of wishes 
and ideals, which are more favorable to the shaping and 
combination of already premeditated ideas than to a 
calm examination of newly originated thoughts. 
Coffee, also, if taken in excess, produces sleeplessness 
and many baneful effects very similar to those arising 
from tea drinking. Coffee, however, produces greater 
excitement, and a sensation of restlessness and heat 
ensues. For throwing off this condition fresh air is the 
best antidote. 
Much depends upon the proper roasting of coffee, in 
which process it loses weight but increases in bulk, 
two pints ot unroasted berries giving three pints when 
roasted. 
Several empyreumatic substances created by roasting 
produce the reddish or brown color, and the tanno- 
caffeic acid, altered by roasting, produces the aroma ; 
the sugar loses a part of its amount of hydrogen and 
oxygen, and is thus decomposed into burnt sugar or 
caramel. 
Liebig states that the berries should be roasted until 
they are of a dark brown color. In those which arc too dark 
there is no caffeine ; and if they are roasted black, the 
essential parts of the berries are entirely destroyed, and 
the beverage prepared from them does not deserve the 
name of coffee. This fact should be noted by drinkers 
of caffe-noir. 
The berries of coffee when once roasted, lose every 
