volves some of the most interesting points buy sildenafil citrate online in the mechanics of
fluids. The resistance to the passage of the fluid being de-
rived chiefly from the friction against the sides of the tube,
will increase in proportion to the ratio of the circumference to
the area of the section. Kow, the circumference of a circle in-
creases directly as the ranbaxy eriacta 100 diameter, while the area increases as the
square of the diameter. The friction is obtained by dividing
the circumference by the area, and therefore cheap sildenafil citrate decreases directly
as the diameter increases, as is shown by tlie following for-
2 a. purchase sildenafil citrate
4 eriacta uk c.
c. order eriacta ~ 2
From which it appears that doubling the diameter of a
tube quadruples its area, eriacta online and at the same time divides the
friction by two.
But, great as is this disparity, it is immensely increased in
practice, especially when tlie tube is of very small calibre and
tortuous or branching. The following experiments serve to
CIECULATIOIS" OF THE BLOOD. 343
show how slight an increase in the diameter of a tube will suf- buy eriacta online
fice to augment its carrying power enormously :
ExPEREsiENT I. — A caoutcliouc tube of 5 mm. bore, and 3
feet long, perfectly straight and of uniform diameter, was found
to transmit a given quantity of water in 115 seconds. An-
other tube, of 6 mm. diameter, but perfectly similar in other
respects, transmitted the same quantity in 65 seconds.
In this case an ranbaxy eriacta increase in the diameter of 20 per cent., sildenafil citrate 50mg and
in eriacta tablets the area of less than 40 per cent,, gives an increase in the cheap eriacta
carrying power of nearly 100 per cent.
Experiment II. — A glass tube 10 inches in length, and
having an inside diameter of .052 inch, gave passage to
drachms of water in 122 sildenafil citrate 100mg seconds. Another tube, of the same
length, and under the same conditions, but having a diameter
of .08 inch transmitted the same quantity of water in 20 seconds.
In this case the addition of one-half to the diameter of the
tube allowed the passage of six times the quantity of ifluid.
Experiment III. — The same tubes were used as in the
last experiment, and all the conditions were the same, except
that defibrinated bullock's blood was employed instead of
water. buy sildenafil citrate The blood was previously strained through very fine
linen. The smaller tube required 1,440 seconds to transmit 6
drachms; while the larger tube gave passage to the same
quantity in 142 seconds.
The ratio here is one-half to ten, instead of one-half to six,
as when water was employed. order sildenafil citrate
In applying the results obtained from these experiments
to the question of counter-irritation, we find that certain stim-
uli applied to the skin act buy eriacta in such a way upon the vaso-motor