8 Burton, Pluvibism in Pottery Workers. 



hydrochloric acid (of about the strength normally found 

 in gastric juice) only a small percentage of the lead they 

 contain. Dr. Thorpe argues, and I believe rightly argues, 

 that if these compounds are used as a means of intro- 

 ducing the lead into glazes, then whatever glaze is 

 accidentally taken into the system, must have its 

 poisonous effects greatly minimised, as only a small 

 percentage of the lead present could pass into solu- 

 tion in the body, whereas at present practically the 

 whole of the lead would be dissolved and absorbed, 

 under similar conditions. The preparation and the 

 general use of fritts of low solubility such as those 

 described are attended with many practical difficulties 

 which seem to me to have been insufficiently considered 

 by Dr. Thorpe and the Home Office. Speaking from 

 practical experience of a number of such fritts, it seems 

 impossible to prepare them under such constant conditions 

 as will ensure the same degree of insolubility. Moreover, 

 the fritts of lowest solubility that we have been able to 

 prepare on the commercial scale are more infusible, and 

 cover the ware less readily, than fritts of somewhat higher 

 solubility. It seems very doubtful if the use of fritts 

 possessing as low a solubility as 2 per cent , which is the 

 standard now proposed by the Home Office, can ever 

 come into practical operation ; nor am I convinced that 

 such a low standard is even necessary, when it is to be 

 combined with the safeguards previously mentioned which 

 are now in operation. Neither has it been shown that 

 such a stringent standard is necessary, or that it obtains, 

 in those continental works where plumbism has practically 

 disappeared. That a low standard of solubility should be 

 set up certainly appears advisable, and it is sincerely to 

 be hoped that, by mutual agreement between manu- 

 facturers and the Home Office, a standard which 



