An attempt to ascertain the absolute toxic possibilities of fritted lead glazes ; White lead and plumbism / by W. Thomason.

  • Thomason, W.
Date:
[1910]
Catalogue details

Licence: In copyright

Credit: An attempt to ascertain the absolute toxic possibilities of fritted lead glazes ; White lead and plumbism / by W. Thomason. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    and if there its only chance of passing into solution depends upon the formation of a soluble lead bicarbonate under the action of the CO2 of the lungs. Such being the case, I have attempted to ascertain the extent to which white lead and lead bisilicate may be taken up in the lungs. For this purpose two lead compounds in varying amounts, suspended ia water at 37° to 40°, were exposed to the action of an excess of CO2 for varying periods. It is found that as a fact both the lead salts are acted upon to a certain degree, but that this degree is very small compared to the gastric extraction under as nearly as possible parallel conditions. Tabi.e O. 250 c.c. water, 37°C, 40°C in all cases, and stream of COj ov'er whole period. I’ooo grm. white lead. 2 hours in contact with CO2. •25 grm. earthenware glaze, 6 hours contact with CO.^ 30 grammes white lead I week's contact PbO in solution in 250 c.c. = ‘ooo8 PbO in solution to •00066 •00066 PbO present =‘09% i'5% •002% • We find in all these cases that the PbO in solution is practically constant, hence it is evident that the reaction is soon stopped by the HjCOg solution becoming saturated with lead bicarbonate, and this point appears to be reached when a concentration of •CX)27 grm. PbO per litre is reached. Similar results have been obtained with bisilicate. It must be remembered that no attempt has been made to reproduce the slightly alkaline and mucous condition of the lungs and air passages, so that probably in the animal itself the action of the CO, is much less rapid than in the above experiment; but even if we accept the above as showing the actual speed of solution we see that it is much behind that of the same amount of white lead in '15 pf^r cent. HCl, even in the presence of considerable amounts of foodstuffs, when the solubility in the same period is not i'5 per cent, but I4’4 per cent. To the best of my belief it is established that though respiration is the means by which lead poisoning is set up it occurs mainly through the stomach, since the main evidence of the lung theory rests on the presumed similarity in action of lead taken into the stomach with much food, compared with that in the absence of food or very little—a similarity which has been shown not to exist.