62 
THE YOUNG SCIENTIST. 
entirely unconscious of the fact tliatit-\yas being 
helped; it would drop the burden at the proper 
point, and run up for another. Indeed my aid 
and presence did not disturb them at all. From 
time to time, the larger of the two, which was 
the female, would thrust her tail with great 
violence down among- tlie pebbles at the bottom 
of the creek and loosen them up, and set free the 
mud which the current quickly carried away. 
The new material thus i)lowed up was carried 
to the nest. Twice in the course of the half 
Jiour that I observed them, the act of spawning 
took place. 
Besides helping move tlie larger stones with 
my staff, I several times plowed up the bottom 
•with its point, thus re^lieving the female of that 
duty. The fish took it all as a matter of course, 
and seized upon the pebbles I had loosened with 
great alacrity. When I thrust my cane beneath 
them and tried to lift them out of the watoi-, 
they would suck fast to the ston(\s and prevent 
me; but they did not manifest any alarm. The 
lampreys become much exhausted with the 
spawning and nest building, and large numbers 
•of them die when it is over. In June it is not 
aimusual to find their dead bodies in the streams 
they mh-dhit— Century. 
Poultry Diseases: Their Prevention and 
Cure. By H. H. Stoddard, Editor of The Poul- 
try World, author of " An Egg Farm," etc., etc. 
Price, 25 cents. Hartford, Conn. 
This little work is by a practical man. and we 
liave been very much pleased with its directness 
and simplicity. While it is true in the case of 
poultry, as of all pets, that cleanliness, good feed 
iind attention to the ordinary rules of hygiene are 
worth all the drug stores on the Continent, still 
it is also true that, in spite of these, occasionally 
a valuable fowl will show symptoms of disease, 
which, if taken in time, may be cured. As for 
eommon fowls, it hardly pays to fuss with them : 
when they are sick, separate them from the rest 
of the yard, give them proper food and quietness, 
and in many cases they will get well. If they die 
of disease, be sure to either burn or boil them 
thoroughly, if the disease is of a malignant char- 
acter. Burying is not safe, even at six feet, for 
the miserable earth-worm will S'o down, bring up 
the germs of disease to tln^ surface, and then, 
when eaten by the otlier fowls, they will infect the 
whole flock. 
We are glad to see that Mr. Stoddard places 
■special stress on the necessity for prevention, 
and lays down simple and accurate rules on the 
subject. 
Scientific Proceedings of the Ohio Mechan- 
ics' Institute. 
In addition to the regular proceedings, this vol- 
nme contains valuable papers on Pumping En- 
gines for Public Water Supply, by John W. Hill, 
M.E. ; Comparative Economy Tests of the Gear- 
ing Boiler Furnace, by John W. Hill. M.E. ; Aver- 
age Weights of Men and Women, by W. A. Col- 
lord; A Criterion for the Measurement of the 
Speed of Chemical Action, by Eobt. B. Warder ; 
Urech's Investigation of the Speed of Inversion 
of Cane-Sugar, by Robt. B. Warder; The Aurora 
Borealis of April 27, 1882, by Chas. G. Boerner. 
The publication is a great credit to the Institute 
of our sister city. Unfortunately the Institute of 
similar constitution in New York (The American) 
publishes no proceedings of its own, and no au- 
thor of a valuable paper would read such before 
it, because his doing so would simply prevent 
recognition elsewhere, and would thus result in 
burying it. 
A Cheap Battery. 
Ed. Young Scientist— 1 have found that by 
taking a common fruit can and filling it about 
three-quarters full of a saturated solution of 
common salt, and then putting about a table- 
spoonful of salt in the bottom, so as to keep the 
solution saturated, placing upon this a piece of 
any kind of paper, and then laying upon the 
paper a piece of common coke, taking care that 
the coke does not touch the can at any point, 
nnd then attaching a wire to the can and an- 
otlier to the coke, quite a constant though weak 
battery is obtained. I have one that has been 
in constant use for over a week, the circuit 
being kept complete all the time. With four 
cells you can decompose acidulated water, salt 
and water, etc.; also deflect the needle of a 
galvanometer very readily, and try a number 
of very interesting experiments. The cost of 
the battery is very little, being from a cent to 
two cents a month at the outside. 
W. C. FOSTEK. 
— Gen. W. H. Hazen, of the Signal Office, in- 
vites people to send him all sorts of popular 
weather proverbs and prognostications. 
— There have been set up in the Grand Opera, 
House at Paris a number of mirrors, measuring 
45x52 ft., and weighing from 1,200 to 1,600 lbs. 
— The Washington monument is fast getting to 
be a big thing. It is now over 300 feet high. When 
completed it will be the highest piece of architec- 
tural work in the world. 
— A French chemist has analyzed the juice of 
the so-called milk tree of Central America, to the 
