Report to Her Majesty's principal Secretary of State for the Home Department on the conditions of labour in potteries, the injurious effects upon the health of the workpeople, and the proposed remedies / by the.

  • Great Britain. Potteries Committee of Inquiry.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Report to Her Majesty's principal Secretary of State for the Home Department on the conditions of labour in potteries, the injurious effects upon the health of the workpeople, and the proposed remedies / by the. Source: Wellcome Collection.

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    thus all the fine particles of lead aro kept in suspension, and readily have access to the body, through the nose, eyes, and ears. Here, under the new conditions of ventilation in the form of an air curtain, it is practically proved that the poisonous dust cannot be inhaled, and the head is surrounded by pure air, without danger to children and young persons. The process can be easily adapted to existing works, and without a large outlay, and will easily repay itself in the increased facility of manufacture. There are no conditions under which poisonous gases cannot be controlled in all staplo trades, so that the wearing of goggles and respirators can be dispensed with. APPENDIX I. Catalogues, Price Lists, &c., have been received from the following and Sanitary Engineers. Ventilating Blackman Ventilating Co., Limited, 63, Fore Street, London. Sturtevant Blower Co., 73, Queen Victoria Street, London. Robert Boyle and Sons, 64, Holborn Viaduct, London. Baird, Thompson, & Co., 159, Queen Victoria Street, London. APPENDIX K. Experiments on the Solubility of Eritts. In my first report on fritts (page 10), I pointed out that the solubility of the lead in weak hydrochloric acid, depended both on the amount of lead present and on the amount of borax present in the frith. With a view to determining with such exactness as was possible, what were the limits within which borax and raw lead might be added to a fritt, I asked Mr. G- G. Leason, of Minton’s, Limited, to prepare a set of experimental fritts containing varying quantities of borax and white lead, along with Cornish stone, sodium carbonate, flint, and whitening. These fritts, after being made, were ground in the usual fashion, and sent to me by Mr. Leason, ready for the dipping tub. The following table shows the per-centage of borax and white lead contained in these fritts. No. 1. Per-centage of Borax and White Lead in Fritts. Number 1 2 3 4 5 6 7 S 9 10 11 12 13 14 15 7* 7o 7„ 7« 7„ % 7n % 7n 7o 7n 7n 7n 7n 7n Borax 10 20 30 10 20 30 10 20 30 10 20 30 10 20 30 White lead - 10 10 10 20 20 20 30 30 30 40 40 40 50 50 50 A gramme of each of these fritts was treated with • 38 per cent, hydrochloric acid for three hours at from 100°-110° F. At the same time some sulphate of lead was treated in the same way as a check experiment. The amount of sulphate of lead dissolved was • 9 per cent., being practically the same as the amount dissolved in the former experiments. On estimating the amount of lead dissolved from each of these fritts, the conclusions of my previous report wero confirmed in a remarkable manner, the amount of load dissolved varying both with the amount of lead present in the fritt and the amount of borax present in the fritt. These results are clearly shown in Table 2. Along the top of the table are placed the per-centages of raw lead in the fritt, and down the side of the table the per-centages of borax in the fritt. Consequently, in order to find any fritt mentioned in Table 1, it is only necessary to draw a line down Table 2, starting from the per-centage of raw lead it contains, and along Table 2, starting from the per-centage of borax it contains, to find the square corresponding to that fritt. On looking at Table 2 it will be obvious at once that the amount of lead dissolved increases horizontally with the increase of the amount of lead present, and increases vertically with the amount of borax present. We may probably assume for the present, until further light is thrown upon, this question by the medical authorities, that fritts in which less than 3 per cent, of the lead is dissolved are practically harmless. All such fritts have been printed in heavy type in Table 2. No. 2. Percentages of Borax in Fritt. Per-centages of Raw Lead in Fritt. 10 10 20 30 40 50 Per-centages of Lead dissol/ed. •3 •5 2 8 5‘0 12-0 20 •6 24 5'0 13-0 15’0 30 13 6-0 14'0 20-0 3G’0 Note.—In the use of fritts in which the per-ccntage of lead and borax added together amount to 00 and upwards, some or the lead chloride formed separates slowly in working, and in the fritt containing 50 of lead and 30 of borax the acid is saturated. On comparing these fritts one with another we find that we can sum up the results of the inquiry in a very simple rule, viz. :— If the per-centage of raw lead and the per-centage of borax in a fritt do not amount, when added together, to more than 40, the fritt may be regarded as practically harmless; but if the per-centage of lead and the per¬ centage of borax, when added together, amount to more than 40, the fritt is probably too soluble to be safely used. It would be interesting to know whether manufac¬ turers of fritts consider this limit practicable for ordi¬ nary glazes. It will be noticed at once that this rule would not include majolica fritts, and that therefore, while doubtless majolica fritts are far less dangerous to use than raw lead, it would be a great mistake to regard them as non-poisonous.