THE YOUNG SCIENTIST. 
123 
water in a is forced up tlirough e b to sup- 
ply its place, and a constant stream is the 
result. It follows from this that under 
ordinary circumstances the point, b, can- 
not be raised more than thirty-two to 
thirty-four feet above the surface of the 
liquid in a. 
B 
Fig. 2. 
To those who keep an aquarium, the 
syphon is not only a useful, but an indis- 
pensable instrument. One of the best 
forms for this purpose is that shown in 
Fig. 3. It will be seen that the legs are of 
Fig 3. 
equal length, and turned up at the ends. 
A syphon of this form may be filled and 
hung up on a nail until wanted, or it may 
be filled in a tub or tank, and then lifted 
out and placed in the aquarium. One of 
the objections to the syphon is the dif- 
ficulty of starting or filling it, and this 
form obviates this to a certain extent. A 
syphon of the form shown has also the 
advantage that it does not disturb the 
sediment at the bottom of the tank, as a 
vertical pipe would do. 
Adulteration of Coffee.— Prof. S. P. Sharpies, 
State Assayer of Massacliusetts, lias been investi- 
gating the character of the ground coffee ordin- 
arily put up in packages. He finds that peas, 
corn, oats, rye, etc., form the chief constituents. 
Fortunately he has not detected the presence of 
any positively injudous substances, and if people, 
who can easily find out the cost of a pound of 
green coffee, expect to buy a like quantity roasted 
and ground for half the price, they deserve to 
drink weak pea soup. For detecting adultera- 
tions he gives the following rules: "Take some 
cold water in a glass and throw upon it about half 
a teaspoonful of the coffee to be tested, stirring it 
around so as to wet the grains. Pure coffee will 
float and scarcely colors the water. Beans and 
chicory sink to the bottom. Chicory colors the 
water at once, beans more slowly. Test the part 
that floats by chewing it. Coffee will thus be 
recognized by its taste. Nut shells, which also 
float, are hard and brittle. A species of nut which 
has lately come into use strongly resembles coffee 
when ground up, by floating on the water as well 
as by its feeling between the teeth; but the dif- 
ference can easily be detected, because the adul- 
terating ingredient is nearly tasteless. After sub- 
jecting the suspected article to the above test, 
spread some of it out on a sheet of paper and 
examine it carefully for grains of rye, oats, and 
peas. The pea ingredient will frecLuently be 
found in pieces one-eighth the size of a pea, and 
the rye in half grains. Chicory is tough when 
taken between tli® teeth, and has a bitter taste, 
different from the bitter of coffee." 
The Fair of the American Institute.— The 
managers of the American Institute have this 
year made an extra effort to increase the attrac- 
tiveness of the fair, and the result is highly satis- 
factory. As usual the fair is specially attractive 
to the young, and forms, indeed, a school of ob- 
ject lessons of the utmost value as a means of 
practical education. Some people, who evidently 
do not appreciate the value of this feature, claim 
that everything that is in the fair can be seen 
elsewhere. True, but not in the same shape or 
so conveniently accessible. There we see every- 
thing presented in the very best manner, so as to 
show its peculiarities and the mode of its opera- 
tion. By all means let the young folks spend 
hour upon hour at the fair. At no other place 
can they learn so much in such a short time. 
Popular Microscopy.— Prof. Starr, of West- 
field. N. J., who, as a lecturer, is well-known to be 
one of the most successful, at least so far as in- 
teresting popular audiences is concerned, has 
just returned from a trip to the West, where even 
in these exciting times he has found interested 
audiences. Sabbath schools and popular asso- 
ciations, who wish a really interesting and in- 
structive lecture and exhibition, would do well to 
correspond with Prof. Starr. 
