590 
NATURE 
[AucusT 8, 1912 
the elaborate pumping appliances and machinery for 
operating the dock. 
Mr. John Horner, of Belfast, contributed a paper 
dealing with the evolution of the flax-spinning spindle. 
Simple in construction, and decidedly effective in use, 
the spindle in its primitive form has descended. from 
remote prehistoric times to the present day. This 
paper is of peculiar interest from the illustrations 
given from photographs of spindles used among primi- 
tive nations; one from the Congo has a whorl made 
from cassava root. Arkwright’s spinning frames are 
also illustrated and described in the paper. 
The commercial utilisation of peat for power pur- 
poses was dealt with by Mr. H. V. Pegg, of Belfast. 
The author has experimented with air-dried, hand-cut 
peat fired into a special form of gas producer. Owing 
to the high and varying percentage of hydrogen in 
the gas, it proved unsuitable for use in the works 
gas-engine. From the experience then gained, it 
appears to be wiser to extract the tar from the gas, 
and, further, that the producer must be comparatively 
non-sensitive to the amount of moisture in the peat 
fuel. 
Mr. Daniel Adamson, of Hyde, presented a paper 
dealing with some conditions affecting the durability 
of wire ropes for lifting appliances. The most im- 
portant of these are the quality of the material and 
the size of the wire, as well as the diameters of the 
pulleys and the arrangements of the ropes. The wire 
used is of crucible steel, having a tensile strength of 
from 80 to 130 tons per square inch. The effect of 
oiling the ropes is found to be very beneficial, increas- 
ing the life of a given rope by two or three times. 
Mr. Charles Wicksteed, of Kettering, read a paper 
on reciprocating  straight-blade sawing-machines. 
Saws were first found in the form of a notched 
bronze knife in the third dynasty, about 5000 B.c. The 
first knives on record were made out of flint, and 
were, in fact, saws with minute teeth. The author 
gives descriptions and illustrations of various types 
of modern hand and power-driven saws. The latter 
machines have now made themselves indispensable in 
modern engineering establishments. 
THE RECENT CONGRESS OF THE ROYAL 
SANITARY INSTITUTE AT YORK. 
qpee Health Congress of the Royal Sanitary Insti- 
tute, which was held at York during the week 
ending August 3, was attended by a large number of 
delegates. Although but few new scientitic facts were 
brought to the notice of the meetings, many papers 
of great interest and value to the public health student 
and worker were read, and some useful discussions 
followed. Reference should also be made to the 
general appreciation of special addresses by the Presi- 
dent (the Archbishop of York), Prof. Karl Pearson, 
and Prof. Henry Kenwood. The following communi- 
cations may claim a special scientific interest. Dr. 
Myer Coplans exhibited an instrument, which is an 
application of the form of ohmmeter which has been in 
use for many years for testing electrical installations, 
for the purpose of obtaining the conductivity of 
liquids. The conductivity of pure water containing an 
electrolytic substance in solution being due almost 
wholly to dissolved matter, it is possible, in very 
dilute solutions, to estimate the percentage amount of 
substances in solution. By such means it was demon- 
strated that a fairly ready method is afforded for 
testing variations in the condition of public water 
supplies, more particularly the effects of sewage pollu- 
tion, water softening, the presence of metals (such as 
lead, iron, or zinc), and the ability of water to take 
into solution dangerous metals when placed in contact 
NO. 2232, VOL. 89] 
with them for any given period, the addition of water 
to mill, &c. Dr. Coplans in another paper dealt with 
some points in the purification of water, in which he 
pointed out that as all particles in suspension, bacteria 
included, show, with efflux of time, a tendency to 
agglutination, and the newly formed aggregates slowly 
sink, if at any time during the process of agglutina- 
tion the so-called bacterial counts are made by the 
usual methods, the results show a considerable reduc- 
tion of the organisms originally present, although in 
reality there is no reason to presume the death of a 
single organism; for if a number of organisms be 
aggregated into a single mass the result of ‘‘ plating,” 
followed by incubation, is but a single colony. He 
concludes that the number of colonies developing, as 
the result of ‘plating,’ followed by incubation, is 
evidence solely of the number of distinct masses: of) 
organisms pre-existing ; there is no relaticnship estab- 
lished as to the total number of organisms originally 
present; furthermore that the methods available . for 
the isolation and recognition of disease-producing 
organisms in water are so faulty as to be altogether 
untrustworthy, in so far as negative results are con- 
cerned. In this connection he refers to the experi- 
ments undertaken at the laboratories of the Metro- 
politan Water Board, in which in 66 per cent. of the 
samples intentionally polluted with millions of germs 
of typhoid fever it was impossible to recover or to 
recognise the dangerous organisms. He concludes 
that with such glaringly defective methods for the 
detection and recognition of dangerous pollution, it 
becomes increasingly necessary to guard jealously the 
purity of our water supplies, a proposition which 
involves an important corollary, namely, the effective 
control and disposal of domestic sewage and slop- 
waters. Mr. A. G. Ruston, dealing with the subject 
of ‘Air Pollution by Coal Smoke,” directed attention 
to the difference between domestic and boiler soot 
obtained from the same coal, domestic soot being 
characterised by its relatively high content of tar and 
volatile substances and its low content of ash. He 
furnished experimental evidence that for every ton of 
coal purchased by the average householder, one 
hundredweight goes up the chimney unconsumed, 
while so far as the factory is concerned there is at 
least a loss of one stone out of every ton of coals. 
In one district of Leeds, the centre of one of the 
chief industrial areas, he finds that fully 4o per cent. 
of sunlight during the year of his investigation was 
shut off by the smoke in the atmosphere, and that 
the solid impurities which reached the ground as 
the result of coal combustion amounted to the high 
figure of 1565 lb. per acre. 
Mr. J. E. Purvis and Mr. G. Walker described 
experiments which demonstrated that as the result of 
the sewage contamination of sea-water, nitrates are 
not formed until after six weeks, when there is a 
coincident increase in the number of bacteria present. 
Other papers specially worthy of reference dealt 
with the subjects of the public health aspects of 
poliomyelitis; the municipal dispensary; the sana- 
torium and tuberculin treatment in the prevention of 
consumption; the physiological effects of exercise; the 
teaching of domestic economy in elementary and 
secondary schools; the housing of the working classes; 
rural housing; housing and town planning; the ven- 
tilation of churches and dwellings; the abolition of 
private slaughter-houses; the hygiene of the steel 
trades; the prevention of wool-sorter’s disease; the 
pollution of streams by coal-washing water and spent 
gas liquor; works for sewage purification in country 
houses; the theory of probable error in its application 
to vital statistics; the eradication of the tuberculous 
milch-cow. 
