MATERIA MEDICA AND THERAPEUTICS.
On the Effect of Coffee. By Dr. Zobel.—In a long and interesting
article Dr. Zobel discusses the effects of coffee as well as, incidentally,
other dietetics. He denies that the use of coffee (and of tea) is to be
estimated by the quantity of nitrogen it contains, and shows by calcu-
lation how comparatively small a quantity of nitrogen could by this
means enter the system. He also denies the accuracy of Rochleder’s
opinions, that coffee gives rise to the formation of creatine, or if it does
so, he questions whether this may not result from its action on the ner-
vous system, and not by immediate transformation of its own substance.
With respect to the influence of coffee on the health, he refers to the
opinions of a few enthusiasts, such as Jury and Thierry, who have
supposed it to be most prejudicial to life. He then inquires what are
the chemical changes which occur in the caffein when introduced into
the blood. The first change he states to be as follows :
fl equiv. hydrocyanic acid C2NH.
1 equiv. caffein CiqNiHioO makes < 1 equiv. of a body of the compo-
f sition C 14N0H9O.
The quantity of hydrocyanic acid is very large, and quite enough to
appear at first sight a justification of those who have asserted the danger
of coffee. But if the examination be continued, this apprehension is
dissipated ; another equivalent of caffein acting on the substance formed
by the separation of the prussic acid, gives rise to four equivalents of
ammonia, the great antidote of the acid, and a third equivalent of caffein
and water gives rise to one equivalent of quinine, two of oil of turpen-
tine, and three of urea, while twenty-seven of oxygen remain. The
formula is thus given :—
3	equiv. caffein=3(C 16 N 4II10 0 4) are C 48 N12 H 30 0 12
23 equiv. water .	.	. are	H 23 0 23
C 48 N12 H 53 O 35
Thence are formed—
1	equiv. hydrocyanic acid .	. C 2 N1IIf
4	equiv.	ammonia	....	N4H12
1	equiv.	quinine	....	C20N1H12O2
2	equiv. oil of turpentine .	.	. C20 Hi6
3	equiv.	urea	....	CeNeH^Oo
27 equiv.	oxygen	....	O27
C48N12H53N35
By the influence of the ammonia and turpentine, the sedative effects of
the hydrocyanic acid are neutralized, and are replaced by a slight stimu-
lant effect on the peripheric nervous system. The ammonia would pro-
duce its stimulant effect, and soon pass off, were it not fixed in some
measure by the strongest neurine tonic known, the quinine. To these
effects of caffein, it is necessary to add those of the tannic acid and vola-
tile oils which the roasted coffee nuts contain, when coffee itself is drank.
Dr. Zobel thus confirms the statement of Lehmann, that the amount of
urea is increased by the use of caffein. A few pages at the end of the
paper are devoted to a consideration of the mode of origin of caffein in
the plant, which we omit.—Brit, & For. Med. Chir. Rev. from Pray.
Viertel. Jahrsch., 1853.