€fte ^^opular Science ^ms 
AND 
BOSTON JOURNAL OF CHEMISTRY. 
Volume XXIV 
BOSTON, JULY, 1890. 
NUMBKH 7. 
CONTENTS. 
Kamii.iak Science. — Simple Scientific Expcri- 
iiieiUs 97 
Brief Studies in Biology 98 
Curious Metliods of Making Fire .... 99 
Further Notes on the Chigger 99 
Wonderful Optical Phenomena 99 
-Culinary Recipes loo 
1'kactkal Chemistry and the Arts. — Car- 
bon 100 
How tlie Burmese Work Their Oil Wells . loi 
The (^ur-DooR World. — A State Convention loi 
A Chapter at the Antipodes 102 
Chapter Addresses, New and Revised . . . lOJ 
Massachusetts State Assembly lOJ 
An Opportunity to Be of Use 10; 
Reports from Active Chapters 102 
Pile-Dwellers 104 
lOiuToRiAL. — A \'isit to the Lick Observatory 105 
Review of Mr. Alfred Russel Wallace's 
"Darwinism" io6 
Meteorology for May, 1S90, with Review of 
the Spring 107 
Astronomical I'henomena for July, 1890 . . 108 
Correspondence loS 
(^lestions and Answers ....... 109 
Literary Notes 109 
.Medicine and Phar.m.vcy. — Vitality . . . 109 
Monlhlv Summary of Medical Progress . . no 
Old Age Ill 
Saccharin in Belgium 112 
Medical Miscellany 112 
PuitLisiiERs' Column 112 
boil, in which the angle of the upper and 
lower faces is (Icterniincd bv the amount of 
inclination given to the tumbler. Although 
I 
Banjlliar Scierjce. 
upon which tiie action of "Barker's mill" 
and all tuibine water-wheels depends — is 
shown in Fig. 2, the only apparatus necessary 
being a clay tobacco-pipe and a little sealing- 
wax. Grind or scrape oW the end of the 
stem, as shown in A, and cover it with a bit 
of sealing-wax, as in B, so that the aper- 
ture at the end is changed into one at the 
side. Then suspend the pipu by a long 
thread, attached to the bowl by another piece 
of wax, and lill the bowl with water. As it 
escapes from the opening in the side at the 
end of the stem, the pre.isnre of the water on 
the opposite side will cau.se the pipe to move 
backwards, away from the stream ; and, after 
a short time, the pipe will revolve tjiiite 
rapidly in a more or less perfect circle. 
To show the power of centrifugal force, 
take a bottle, fill it with water, and then 
SIMPLE SCIENTIFIC EXPERIMENTS. 
A PLAIN' glass tumbler, one-third full of 
water, forms an admirable substitute for a 
glass or liquid prism, to illustrate the refrac- 
tion and dispersion of a ray of light. Take 
a sheet of thick paper, cut a narrow slit 
through it, and hold it in the siudight so that 
the image of the slit shall be thrown upon a 
sheet of white paper placed on a table 
beneath. At first only a bright image of the 
slit will appear ; but, if the tumbler (jf water, 
heltl inclined at* an angle, — as ^own in the 
illustration, — is placed in the j)atli of the 
lieam of light, not only will the course of the 
lieam as a whole be lefractetl, or bent out of 
a straight line, but the liglTt itself will be 
more or les.s perfectly decoinposetl into its 
constituent colors, forming a miniature solar 
-.pectnim. The etlect is rendered more strik- 
ing by cutting two slits in the paper along 
side of each other, so that the light passing; 
through one goes direct to the paper screen' 
liclow, while the other goes by way of the 
imjxovised prism. An examination of the 
illustration will show that the glass of water 1 
really forms a true liquid prism, similar to 
the more perfect ones of bisulphide of car- 
a dark room with an aperture for the light to 
enter is unnecessary in this experiment, such 
an arrangement, where available, would be a 
great improvement; and, by filling the air 
with a little smoke or du.st, the entire course 
of the beams of light may be easily traced. 
A HK,\irrii'l'i,T.Y simple and elVective illus- 
tration of the reaction of a stream of water 
escaping from an aperture — the principle 
invert it until all the water has, ai>parently, 
run out. One would naturally say that only 
two or three drops remained atlhering to the 
interior, but, if a sheet of blotting-paper is 
placed on a table, and the bottle — having 
been firmly grasped as shown in the engrav- 
ing — is moved rapidly in the arc of a circJc, 
with the iiioulh dircctetl towards the paper, a 
sin|)risingly large number of dro|)s will be 
found to have been absorbed by it. This is 
due to a twofold action of the centrifugal 
force develojied by the motion of the bottle. 
The considerable amount of water adhering 
to the inside of the bottle is driven out of the 
mouth, and also broken up into a great num- 
