un 
6 NATURE 
| NOVEMBER 15, 1906 
describes his early experiments in telegraphy over a 
distance of a mile and a half. The equipment of 
the seismographic department of the geophysical 
institute is in every way unique, and the new earth- 
quake house built by Prof. Wiechert in 1902 is prob- 
ably one of the finest in the world. 
It is beyond the scope of this article to go into 
detail on each of these developments, but a study of 
the volume shows that the facilities provided for the 
student at Gottingen appear to be fairly comparable 
in a general way with those now available at Man- 
chester, where the splendid new laboratories of Prof. 
Schuster at the University, and of the College of 
Technology in the city, provide together all that 
could be desired for a complete course of training 
and research in almost any branch of either the pure 
or applied science. Though there is much at each of 
the two universities which cannot be compared to 
any similar thing at the other, yet many details make 
the resemblance between the equipments for pure 
physics distinetly striking ; for example, each possesses 
a large concave Rowland grating, with mounting 
specially designed for accurate photographic work, 
made by Krupp and by Sir Howard Grubb re- 
spectively. The magnificent equipment at Manchester 
has already rendered excellent service in the hands 
of Mr. Duffield in his investigation of the effect of 
pressure on arc spectra. 
The volume under review is well got up, and 
though considerable space is taken up with purely 
descriptive detail, there is much matter in it of real 
interest; for example, many passages in the speeches 
delivered at the opening ceremony sparkle in a 
manner not usual in such efforts. We conclude with 
a translation of some extracts from the address of 
Prof. Voigt. He says :— 
“What is it, then, which fetters the crystallographer 
so strongly to his science? I will try to explain it 
by a parable. 
““ Let us imagine in a large hall a couple of hundred 
brilliant violin-players, who all play the same piece 
with instruments faultlessly tuned, but commence 
simultaneously at all sorts of different places, and 
perhaps at the conclusion begin over again. The 
effect is (at least for Europeans) not exactly pleasant, 
a monotonous jumble of sounds, in which even the 
finest ear is unable to recognise what is being played. 
Such music the molecules of g’aseous, liquid, 
and ordinary solid bodies make for us. They may be 
highly gifted molecules with marvellous internal 
architecture, but in their activity each disturbs the 
others. . . . A crystal on the contrary corresponds to 
the orchestra above described, when the same is led 
by a vigorous conductor, when all eyes intently watch 
his nod, and all hands follow the exact beat. . 
This picture renders it understandable how crystals 
can exhibit whole ranges of phenomena, which are 
absolutely lacking in other bodies. In my opinion 
the music of physical law sounds forth in no other 
department in such full and rich accord as in crystal 
physics.”’ 2 JE RAR EAR KER® 
THE ETIOLOGY OF SLEEPING SICKNESS. 
MONG the scientific achievements of the last 
decade, few have been so remarkable as the 
rapid increase of knowledge with regard to the 
minute animacules termed by zoologists Protozoa. 
More especially is this true as concerns the parasitic 
members of the group and their relation to disease 
in man and beast. It is now known that protozoan 
1 “Glossina palpalis in its Relation to Trypanosoma gambiense and 
other Trypanosomes (Preliminary Report)."’ By E. A. Minchin, A. C. H. 
Gray and the late F. M. G. Tulloch. With 3 plates, 1 map and rr text- 
figures (Proc. Roy. Soc., 1906.) 
NO. 1933. VOL. 75| 
: mess. 
parasites are the cause of many diseases, especially in 
the tropics, and as a type of such we may refer to 
malaria, since the etiology of this disease is now so 
thoroughly known that it may serve as a model, as 
it were, of diseases due to Protozoa, and at the same 
time furnishes valuable analogies and suggests the 
problems to be investigated in other cases. 
The classical researches of Laveran, Ross, and 
others have resulted in establishing clearly the cause 
and nature of malaria, and have proved definitely 
(1) that the illness is due to a minute protozoan para- 
site present in the blood and multiplying there; 
(2) that the disease is transmitted from sick to 
healthy persons by certain biting gnats or mosquitoes, 
a mosquito which has sucked blood from an infected 
person being capable, after a certain period of 
time, of inoculating other persons with the malarial 
parasite at subsequent feeds; and (3) that the para- 
site is not carried merely passively by the mosquito, 
but passes through an essential part of its life-cycle 
within it, since sexual forms of the parasite are 
developed which conjugate and multiply in the 
digestive tract of the mosquito in a manner different 
from the mode of multiplication in the blood of the 
patient. It is not extraordinary that diseases of this 
type should be especially prevalent in the tropics, 
where insect life is so richly developed, and the 
numerous blood-sucking insects of all kinds furnish 
the requisite means of transmitting and disseminating 
the parasitic micro-organisms. 
Since Livingstone’s time it has been known that 
horses and cattle in Africa die from a disease pro- 
duced by the bites of the indigenous tsetse-flies. 
These flies, of which eight species are now known, 
belong to the genus Glossina, a genus of Diptera or 
two-winged flies characteristic of the African fauna, 
and not found on other continents. The disease 
which they produce, termed nagana, or tsetse-fly 
disease, is rapidly fatal to imported cattle or horses, 
but does not affect human beings. Various suppo- 
sitions were put forward as to the nature of the 
malign power exerted by the dreaded tsetse-fly until 
the discoveries of Bruce solved the problem once and 
for all. Bruce found that the disease is caused by 
the presence in the blood of a minute flagellated 
organism belonging to the genus of parasitic 
Protozoa already known to zoologists by the name 
Trypanosoma, and that the parasite is transmitted 
from sick to healthy animals by the bite of the tsetse- 
fly, which was thus shown to play a part in the 
dissemination of nagana analogous to that played 
by the mosquito in the dissemination of malaria. 
Bruce’s researches established for nagana the first 
two propositions stated above for malaria, but it re- 
mained to be proved whether the parasite did or did 
not undergo a definite developmental cycle in the 
tsetse-fly, as the parasite of malaria does in the 
mosquito. Bruce discovered, however, another fact 
of great importance, namely, that the ‘* trypano- 
somes *’ of nagana are to be found in the blood of 
indigenous. wild game, such as antelopes and 
buffaloes, to which the parasites appear to be 
innocuous. These infected wild animals serve, how- 
ever, as a reservoir for the disease, the trypanosomes 
being conveyed by the tsetse-fly from the indigenous 
wild animals to the susceptible domestic animals. 
No such natural “ reservoir ’’ has been proved as yet 
for the malarial parasite, though its existence has 
often been suspected. 
It had long been known that negroes from the 
west coast of Africa were liable to a slow but fatal 
disease, which, from the peculiar comatose symptoms 
seen in the final stages, was termed the sleeping sick- 
Nothing was known as to the nature of this 
