
AUGUST 12, 1915] 
that the recovery of ammonia is not likely to be profit- 
able unless the nitrogen content exceeds 15 per cent. 
calculated upon absolutely dry peat. Finally, he shows 
that under favourable conditions power can be gene- 
rated from certain ef these Canadian peat bogs at a 
cost equal to or below that at which it can be obtained 
by the utilisation of water-power. A little attention 
is also devoted to the question of the utilisation of the 
lignites of certain of the Western Provinces, where 
true bituminous coal is not obtainable locally, and it 
is shown that in certain circumstances it toc can be 
employed profitably in the generation of gas. 
The second report is intended to aid, not only the 
mining industry, but also the very large number of 
manufacturing industries that depend to a greater or 
lesser extent upon an adequate supply of raw materials 
in the shape of mineral products. The report deals 
with a very large number of miscellaneous minerals, 
of which asbestos, barytes, clay, lime, and sand are 
perhaps the most important, and it should be noted 
that such minerals as are used in Canadian manu- 
factures but are not produced in Canada are referred 
to, as well as the minerals of domestic production. 
It is noteworthy that quite a considerable quantity 
of minerals is imported, although they could be pro- 
duced in the Dominion, and one of the main objects 
of this report is to bring actual or possible producers 
and consumers into closer touch with one another. 
The object is an excellent one, and such reports as 
this should prove of the greatest value to both parties 
and should help towards that very desirable object, the 
industrial independence of this great Dominion. 
The report of the Chief Inspector of Mines of the 
State of Mysore for the year 1913 has just been issued. 
Apart from the statistical portion, which shows that 
the value of the bullion produced during the year in 
question was 2,150,193/., a decrease of 0-37 per cent. 
from the previous year, the chief general interest in 
this report is to be found in a careful investigation of a 
shaft accident at the Mysore Gold Mine. It appears 
that the steel pin, which secured a driving clutch, that 
connected the engine shaft and the winding reel sud- 
denly broke, allowing the cage, in which forty-two 
miners were travelling, to fall to the bottom of the 
shaft. An investigation was held into the cause of the 
fracture of this pin and into the reason why the power- 
ful brake attached to the winding engine did not hold 
the reel, and the report of the committee of inquiry 
is now given. It cannot be said that the cause of 
the fracture is satisfactorily explained, but the in- 
sufficiency of the braking arrangements is very 
clearly demonstrated. Having regard to the fact that 
this brake is of the construction that is in general use 
on winding engines in all parts of the world, this 
report deserves the careful attention of all who have 
to do with winding from deep shafts by means of the 
powerful winding engines that are in general use in 
modern mines; in particular it may be noted that the 
brake appears to have complied fully with the pro- 
visions of our Coal Mines Act, and yet was found 
inadequate to prevent the very serious accident in 
question. 
Another interesting section in this report deals with 
accidents due to “air blasts,’’ which caused no fewer 
than thirty-one deaths during the year in question. 
These air-blasts consist in the sudden flying-off of 
huge masses of rock from the walls of stoped-out 
portions of the deposit, the action being extremely 
violent and suggesting that the rock is under some 
condition of great strain that suddenly relieves itself. 
The phenomenon is as yet but little understood, and 
all measures taken for combating this danger are 
still of a more or less tentative character. 
NO. 2389, VOL. 95] 
NATURE 


659 

TRYPANOSOMES CAUSING DISEASE IN 
MAN AND DOMESTIC ANIMALS IN 
CENTRAL AFRICA. 
“THESE lectures are confined to a consideration of 
the trypanosomes causing disease in man and 
domestic animals in Central and Southern Africa. 
The conditions, however, which obtain on the east and 
west coasts of Africa between 20° N. and 30° S, lati- 
tude are much the same as those which are found in 
the central parts, and it is probable that the same 
trypanosome species are found throughout. So that 
in describing the species found in our own colonies it 
may be assumed that all the important pathological 
species found in Central Africa are being dealt with, 
although in other places they may be known by other 
names. 
The central region—the tropical or equatorial—cor- 
responds with the distribution of the tsetse-flies, and 
the trypanosomes causing disease in this region are 
carried from sick to healthy animals by various species 
of this genus of flies. In the north of Africa, outside 
the range of the tsetse-flies, two trypanosome diseases 
| are found, one of the horse (dourine), and another of 
camels (surra), the former conveyed from sick to 
| healthy horses by contagion, the latter almost certainly 
by large biting flies, the so-called horse-flies, or 
tabanide. 
CLASSIFICATION OF THE AFRICAN ‘TRYPANOSOMES. 
The three characters mainly relied upon in this 
classification of trypanosomes are, in the first place, 
their morphology; secondly, their pathogenic action on 
animals; and, thirdly, their mode of development in 
the tsetse-flies. They may be divided into three 
in 
groups, and these are set out the following 
scheme :— 
Group A. Trypanosoma Brucei Group. 
1. Trypanosoma brucet. 
2. Trypanosoma gambiense. 
3. Trypanosoma evansi. 
4. Trypanosoma equiperdum. 
Group B. Trypanosoma Pecorum Group. 
1. Trypanosoma pecorum. 
2. Trypanosoma simiae,. 
Group C. Trypanosoma Vivax Group. 
1. Trypanosoma vivax. 
2. Trypanosoma caprae. 
3. Trypanosoma uniforme. 
These names probably represent most of the prin- 
cipal pathogenic trypanosomes discovered up to the 
present time in Africa. The northern species, Try- 
panosoma evansi and T. equiperdum, are placed in 
the first group, as they seem by morphology and 
their action on animals to belong there, Each group 
is distinguishable or separable by well-defined char- 
acters. 
Group A. The Trypanosoma brucei Group.—The 
species forming this group (Fig. 1) are all more or less 
polymorphic, varying in size and shape from short and 
stumpy forms without free flagella to long and slender 
forms with free flagella. The cytoplasm contains 
numerous dark-staining granules. The micronucleus 
or kinetonucleus is small, and is situated as a rule 
some distance from the posterior extremity. The un- 
dulating membrane is well developed and thrown into 
bold folds. 
1 Abridged from the Croonian Lectures delivered before the Royal College 
of Physicians of London on June 17, 22, 24, and 29, by Sir David Bruce, 
C.B., F:R-S. 
