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42
Fertilisers and
Feeding
Stuffs Act,
1926
The Chemist-in-Chief is the official agricultural analyst under the Fertilisers and
Feeding Stuffs Act, 1926, for the County of London, excepting those parts within the
purview of the City Corporation and Port Sanitary Authority.
110 samples were examined under the Act and, of these, 52 were found to vary in
some particular from the statutory statements or voluntary warranties given or to have
deficient or incomplete statements. In only one fertiliser and two feeding stuffs were the
differences clearly to the disadvantage of the purchaser. Three unscheduled feeding
stuffs contained so much fibre as to be of very little nutritional value and one contained,
in addition, a very high proportion of chalk or ground limestone.
Oils and polishes
Lubricating
and other
oils
Samples of many different lubricating oils were examined for use in steam engines,
diesel and gas engines, thrust bearings, and motor vehicles generally, in order to ascertain
that they were suitable for the purpose required or that they complied with the requirements
of the specification. Attention is constantly drawn to the fact that a clear oil from
a streamline filter is not necessarily fit for use because it may contain a large quantity
(10 per cent.) of' heavy ends' of the fuel which reduces its load carrying capacity and,
furthermore, the acidity may be unduly great. One instance was reported where the
grade of oil supplied was unsuitable for the machinery for which it was intended and
this was discovered before use, otherwise bearing trouble would most probably have
occurred. Bearing trouble was reported from a pump which was thought to be due to
the oil in use ; examination showed this not to be so but that it had occurred because of
the pressure of water in the crankcase.
Polishes
This category includes many types of polishes for various purposes ; for example,
wax polishes in white spirit, water emulsion polishes, metal polishes for silver and brass
and also oils tor floor treatment.
The wax polishes generally complied with the specifications, although occasionally
comment was necessary on a deficiency of wax. Attention is frequently drawn to the fact
that these polishes are not allowed to dry sufficiently after application and before
polishing, which leads to unjustifiable complaints in respect of quality. Many water
emulsion polishes were examined and a general failing was poor water resistance.
Complaint of the odour of metal polish was proved to be due to the quality of the
ammonium soap used to assist emulsification and cleansing ; this was remedied by the
manufacturer. A sample of floor sweeping compound was found to have an excess of
sand (the cheapest constituent).
Disinfectants and air deodorisation
During the year under review, not only were periodical tests made of the standard
specification items but a variety of proprietary products were examined as to their
potential usefulness. In the former group, criticism was made of emulsion instability and
the staining of linen, both points being regarded as of considerable importance. The
proprietary products included the chlorxylenol and quaternary types and, at the present
time, it is not considered that the latter should be regarded as satisfactory general disinfectants
although, for particular purposes, their activity is very high. A sterilising gel
containing synthetic detergent and a quaternary germicide was claimed to be effective
for the cleaning of kitchen equipment, etc., but it also included sodium sulphate and
was not recommended because of corrosion possibilities.
The problem of air deodorants again arose and proprietary compounds for this
purpose and appliances for producing fine sprays were examined. Most of the materials
could only be considered to have an aesthetic value and, in most instances, cleanliness
and proper ventilation were recommended. In a special case of a home for the aged
various cheap, pleasant smelling compounds were tried experimentally. However, the
lasting power of the essential oils increases with their cost and, unless considerable