AuGusT 19, 1915] 
NATURE 
: 685 

mology of the Union, who, convalescent from an ill- 
ness which narrowly escaped being fatal, “had left 
South Africa on a six months’ tour in Australia and 
the United States. His address was a discussion 
of some phases of the locust problem. The author 
expressed the opinion that the Union is entering upon 
a cycle of years when locusts will be widespread and 
destructive. The species of locusts that periodically 
ravage South Africa were described, the principal 
being the red and the brown locust, the former being 
congeneric with the large North African locust and 
that of the Argentine, while the brown locust is con- 
generic with the migratory locusts of Europe and 
Asia. The effects of climatic conditions on locust 
migration were discussed, as well as the causes of the 
excessive multiplication. The concluding paragraphs 
of the address dealt with the enemies of the locust. 
In Section D the presidential address was delivered 
by Mr. J. E. Adamson, Director of Education of the 
Transvaal; its subject was ‘‘The Control of Educa- 
tion,’ and it laid down the principle that the control 
of school education should henceforth be vested in the 
Central Government of the Union and not in the 
executives of the provinces. It was, he said, a dictate 
of the national conscience; moreover, national educa- 
tion is a vital factor of national progress, and, in addi- 
tion, national schools should reflect national aims and 
aspirations. That there was divergence in South 
Africa regarding these aims and aspirations was only 
a further reason for discussing them in a national 
assembly. Wise and impartial administration would 
only be secured if it were in the hands of a body repre- 
senting wide and varied interests. 
With regard to the papers read at the various sec- 
tional meetings only brief summaries can be given. 
In Section A Mr. A. H. Reid contributed a useful 
review of the leading classes of fire-resisting mate- 
rials used in building construction, while from the 
naval engineer’s point of view Mr. H. C. Kenway 
discussed certain aspects of modern naval development. 
The president of the association, in a paper on the 
masses of visual double stars, gave a table containing 
all double stars for which fairly trustworthy orbits 
had been computed. Dr. A. W. Roberts had a paper 
on secular change in the period of m Carinz, the 
variation of which star was discovered at Lovedale 
in 1891. The discrimination of the conic by Prof. 
Dalton, and the gamma, or factorial function, by 
Prof. Roseveare, were types of the heavier mathe- 
matical papers read in the section. Mr. E. Jacot, 
discussing the measurement of the natural ionisation 
of the air, contrasted the results obtained by the 
Gerdien and by the Ebert forms of apparatus, and 
showed that these results are not comparable. 
In Section B Prof. J. A. Wilkinson, in a paper on 
“The Profession of Pharmacy,” urged the need of 
reform, and pointed to the fact that South Africa as 
yet offers no pharmaceutical training in any of her 
colleges, and that materia medica and toxicology are 
nowhere taught. A paper on the Rand gold, by Prof. 
E. H. L. Schwarz, discussed the three classical 
theories as to the origin of the gold, and expressed 
his preference for the placer theory. Another contri- 
bution by the same author had for its subject ‘‘ The 
Fault Systems of the South of Africa... Dr. W. A. 
Caldecott read an important paper entitled ‘‘ Some 
Features of the Rand Gold Mining Industry,” in which 
he set forth the main results of the operation of the 
Witwatersrand gold mines during the past twelve 
years. Dr. C. F. Juritz, in a paper on the chemical 
composition of Karroo ash, directed attention to the 
fact that large quantities of burnt sheep manure had 
accumulated throughout the Union during many 
years, and contained up to 1g per cent. of potash, 36 
per cent. of lime, and 6 per cent. of phosphorus 
NO. 2390, VOL. 95] 

pentoxide. An interesting paper on the ! Naras plant 
(Acanthosicyos horrida) was contributed by Dr. W. 
Versfeld and Mr. G. F. Britten, describing the nature 
of the plant and its edible fruit, which is either con- 
sumed as gathered, prepared as soup, or made into 
cakes. Analyses were given of the fruit and of soils 
where the plant grows, and where it refuses to grow. 
Mr. A. Stead contributed a paper on the ash of the 
“alkali bush,” in which he found 32 per cent. of 
potassium carbonate and 19 per cent. of sodium 
carbonate. 
In Section C Prof. Schénland criticised Lotsy’s 
theory of evolution, which, he declared, has not 
brought us a step nearer the vera causa of evolution. 
Mr. R. W. Thornton, principal of the Middelburg 
School of Agriculture, treated of the ostrich feather 
industry in South Africa, covering briefly, in addition 
to an historical introduction, the subjects of incubation, 
rearing, parasitic diseases, and feather marketing. An 
exhaustive analysis of South African agriculture was 
submitted in a paper by Mr. P. J. du Toit, Acting- 
Secretary for Agriculture of the Union, and it showed 
the marvellous agricultural progress of the country 
during late years, particularly since 1905. Mrays 
Burtt-Davy contributed a paper on his experiments 
in cross-breeding Persian and Merino sheep. Of the 
thirty-six papers submitted to Section C, only two can 
be adequately summarised here. These are Dr. A. L. 
Orenstein’s paper on prevention of malaria, and Dr. 
Watkins-Pitchford’s on miners’ phthisis. 
Dr. A. L. Orenstein read before Section C a paper on 
the problems and principles of malaria prevention, in 
which he outlined the following five lines of attack :— 
(1) The elimination of human carriers only; (2) the 
reduction to a non-infective minimum of the number 
of anophelinze of the species capable of transmitting 
malaria; (3) the protection of the individual against 
the bites of mosquitoes; (4) the protection of the indi- 
vidual by proper medication against the development 
of the parasites within the blood; and (5) a combina- 
tion of several or all of these methods. Of these 
methods the first is fraught with almost unsurmount- 
able difficulties, the second method being the plan 
most generally acknowledged to be the most promising 
of results. Dr. Orenstein described malaria prevention 
as a highly specialised field of sanitation, and any 
large-scale scheme as a costly undertaking which 
should only be entrusted to specialists in this branch. 
Dr. Watkins-Pitchford’s subject was ‘‘ Miners* 
Phthisis on the Rand.” He emphasised the not gener- 
ally recognised distinction between pulmonary silicusis 
and miners’ phthisis. Silicosis due to the inhalation 
of air containing fine particles of quartz, etc., was 
rarely fatal; it became the much more serious disease, 
miners’ phthisis, when the damaged lung became in- 
fected by the tubercle bacillus. The suppression of 
the disease would be obtained by action in two direc- 
tions : preventing the inhalation of dust by workers in 
the mines, and excluding from the mines all those who 
were expectorating the tubercle bacillus. The proposi- 
tion of abolishing miners’ phthisis from the Witwaters- 
rand he considered quite feasible, provided always that 
both the workers and the management co-operated 
in the common cause. 
Dr. C. L. Leipoldt, medical inspector of schools for 
the Transvaal, in a paper read before Section D, 
stated that the percentages of men of the burgher 
commandos of the Transvaal province rejected for pre- 
ventable and remedial defects were far higher than 
they were in conscript armies in countries where medi- 
cal inspection of schools had been in vogue for years. 
It was clear that a large percentage of the adult popu- 
lation suffered from remedial and preventable diseases, 
which appreciably affected their wage-earning capacity 
and consequently the national efficiency. He sug- 
