March 31, 1870 | 
NATORE 
552 
OUR BOOK SHELF 
The Literature and Curiosities of Dreams. A common- 
place Book of Speculations, concerning the mystery 
of Dreams and Visions, records of Curious and 
well-authenticated Dreams, and Notes on the various 
modes of Interpretation adopted in Ancient and 
Modern Times. By Frank Seafield, M.A. 2nd. Ed. 
Revised; pp. 518. (London: Lockwood and Co, 
1869.) 
IN this book the author has gathered together almost 
every kind of information on the subject of which it treats. 
The compilation of it has doubtless been a labour of love, 
and the author’s great object has been to select, from all 
sources, whatever is most characteristic of his opinions 
which have been held on the subject of Dreams, and also 
all the best examples upon which these opinions have been 
founded. He tells us that no amount of research has 
been considered irksome or irrelevant, so that, in his 
opinion, “there is nothing extant in the way of dream- 
speculation or anecdote which is not fairly and impar- 
tially represented.” The book is, in fact, a rich and 
methodically arranged storehouse of dreams and of 
opinions thereon, which will be valued by many who are 
merely curious, as well as by those who are more seriously 
interested about their causes and phenomena. It is likely 
to serve as a book of reference, or as one which may be 
had recourse to in spare half-hours, rather than as a work 
which will be taken up to be at once read and mastered. 
Untersuchungen iiber Psychologie. Anmerkungen su 
Robert Zimmermann’s “ Philosophische Propadeutik.” 
Mit Riicksicht auf Herbart, F. H. v. Fichte, Ulrici, 
Fechner, Lindner, Drébal, Fliget, Nahlowsky, Lange, 
Darwin, C. Vogt, L. Biichner, Moleschott, Lotze, Hoppe, 
u.5.w. Won Dr. F. A. v. Hartsen. (Leipzig, 1869.) 
Untersuchungen iiber Logik. Mit Riicksicht auf Apelt, 
Bolzaus, Drbal, Gratry, Kuno Fischer, Hegel, 
flerbart, Kant, Maudsley, F. Stuart Mill, Striim- 
pell, W. Schuppe, Trendenburgh, Ueberweg, 
k. Zimmermann, usw, Von Dr. F. A. v. Hartsen, 
(Leipzig, 18609.) 
THESE publications by Dr. Hartsen are somewhat discur- 
sive criticisms of disputed matters in psychology and 
logic, and of the opinions of the different authorities whose 
names are mentioned on the title-pages. Neither of them 
lays claim to give a systematic account of the subject 
with which it deals, and both of them have the character 
of critical articles suited to a review, rather than of 
treatises. The “Psychological Inquiries” consist entirely 
of discussions upon Zimmermann’s “ Empirical Psycho- 
logy,” paragraph by paragraph, references being made to 
the numbered paragraphs in the original work. It will be 
obvious that this plan of procedure is rather trying to the 
reader who is obliged to guess from the critical observa- 
tions at the nature of the opinions that are in question, 
and whose interest is not easily kept up inso desultory a 
disquisition. Nevertheless, if he is content to persevere, 
he will meet with much that is suggestive and instructive. 
The “Logical Inquiries,” though not systematic and com- 
plete, will in like manner repay perusal ; they are contri- 
butions to the foundation of a system of scientific logic. 
Kurses Lehrbuch der Physiologie des Menschen, Von 
Dr. E. Larisch. (Marburg: Oscar Ehrhardt, Lon- 
don: Williams and Norgate.) 
THIS is very similar to Budge’s little work, but smaller, 
and written in more of a narrative style. It therefore 
contains less matter, and this is especially the case in the 
part relating to the nervous system, Dr, Larisch has not 
the scientific eminence of Prof. Budge, and therefore 
speaks with less authority ; on the other hand, he is free 
from the temptation of attaching too much importance to 
his own researches and views. 
LETTERS TO THE EDITOR 
[The Editor does not hold himself responsible for opinions expressed 
by his Correspondents. No notice is taken of anonymous 
communications. | 
Formation of Ground Ice 
I THINK the enclosed letter contains as good a description of 
the formation of ground ice as I have hitherto seen ; I therefore 
send it to you, thinking it of sufficient interest to appear in 
NATURE. Joun TYNDALL 
Royal Institution, March 27 
To PROFESSOR TYNDALL 
I have been engaged since September last in making a survey 
for the Intercolonial railway, up the valley of the Matapediac, a 
stream about two hundred feet in width and four or five feet in 
depth, which discharges into the Restijinche river, about twenty 
miles above the head of the Baie des Chaleures. 
The Matapediac, which is fed by large fresh water springs, 
runs over a rocky bottom covered with loose stones, ranging in 
size from coarse gravel to boulders as large as a hogshead, and 
the average current is about four miles an hour. 
Early in November last the temperature went down in one 
night to 12°F., and on going out of camp the following morning 
I noticed large quantities of what appeared to be snow saturated 
with water floating down the stream, but nota particle of snow 
had fallen near us or for many miles round, as far as I could see 
by the mountain tops, nor had any ice formed on the surface of 
the river. 
The water opposite where I stood was about six feet deep, and 
perfectly clear, so that I could see every stone on the bottom, 
and with the exception of the floating slush, the river was as it 
had been the previous day when the temperature was about 
50° F. ; I got into a canoe and paddled with the current for 
half a mile or so, and in shooting some small rapids, where the 
water in places was not more than two or three feet deep, I 
noticed on the bottom, masses of the slush clustered round and 
between the boulders, and a slight touch with the paddle was 
sufficient to free these clusters, when they rose to the surface, and 
were carried away bythe current. I continued down the stream 
for three or four miles, and noticed the same thing in every rapid, 
where the water was shallow and ruffed by stones at the bottom. 
The buoyancy of this slush was such that when detached from 
the bottom it rose so rapidly as to force itself well out of the 
water, and then floated off about half submerged. 
T watched this forming of slush for many days, and in several 
cases found small stones imbedded in the floating slush, having 
been torn from the bottom when the buoyancy of the slush, aided 
by the running water, caused it to rise. 
The temperature continued getting lower daily, and the slush 
in the rapids formed more rapidly than it was carried away, so 
much so that a bar or dam was formed across the river at 
each rapid, backing up the water in some cases five and six feet, 
when it generally found an outlet over the adjoining land, and 
into its natural bed again, or the head of water became sufficient 
to tear away the obstruction, which by this time had become 
a solid frozen mass. 
All this time, no properly crystallised ice had formed on the 
surface of the river, the current being too rapid, but the slush or 
“anchor ice” as the trappers call it, was forming in deeper 
water than it had formed in before, indeed all over the river 
bottom, and was rising and floating away as I have already 
described, Eventually the temperature got down to two and 
three degrees below zero, when the river surface began to freeze 
in the eddies and along the edges, and the open water space be- 
came narrower every day, and was filled with floating ‘*‘ anchor 
ice’’ and detached masses of solid ice, which here and there be- 
came jammed and frozen together, so as to form ice-bridges on 
which we couid cross. 
These ice-bridges served as booms to stop much of the floating 
ice, which froze solid the moment it came to rest ; and in this 
manner the river at last became completely frozen over for about 
forty miles of its length, but not until after we had experienced 
five weeks of steady cold, with the thermometer never above 
+12° F., and frequently down to — 16° F, 
It is just possible that what I have endeavoured to describe may 
suggest something to you, or it may be an old story ; if so, please 
pardon the intrusion. W. G. THomMPson 
Dalhousie, N.B., February 18 
