On the presence of arsenic in the vapours of bone manure : a contribution to sanitary science / by James Adams.

  • James Maxwell Adams
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: On the presence of arsenic in the vapours of bone manure : a contribution to sanitary science / by James Adams. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    81/84 page 79
    It appears, therefore, that 21-6 per cent, or, in round numbers, more than one-fifth part of all the arsenic contained in pyrites, passes into, and is retained in, the sulphuric acid. I have already explained how' it is that this average estimate may frequently exceed or fall short of the actual amount. Proposition Fourth, p. 41.—An absolutely pure sulphui-ic acid may not be required for many manufacturing operations. _ But it is of prime importance that manufacturers should recognise, in a manner not hitherto done, the fact that, in the arsenical contamination, there is a potential element of danger, as illustrated in the present enquiry. And acid manufacturers should not continue, as at present, to employ the very crudest processes, seeing that, with extremely little cost, these processes may be modified, with the result of effecting a very great improvement in the quality of the acid. I have seen and tested such a simple modification, resembling somewhat the process of M. Oliver. In this process the gases disengaged from the burning pyrites are carried along a tortuous flue, in an up and down manner, a portion of the flue, 20 or 30 feet long, consisting of an iron pipe immersed in water, and ending in a precipitating chamber, in con- nection with the leaden chambers. By means of this arrangement, the gases and metallic fumes are cooled, and a considerable deposit of solid particles takes place before they enter the vitriol chamber. This deposit has been analysed by Mr. R. C. Clapham, and found to consist of, in round figures, 59 parts of arsenious acid, 8 parts of iron, lead, copper, zinc, and sand, and 33 parts of sulphuric acid and water. Proposition Sixth, p. 43.—Among professional or manufactur- ing chemists there is one gentleman of admitted pre-eminence for his scientific skill and unapproached practical experience in all that con- cerns the chemistry of artificial manures. He is thus referred to in the latest edition of the English Cyclopsedia:—Mr. J. B. Lawes, of Rothamsted, Hertfordshire, who has lately sold to Lawes' Chemical Manure Company his manure manufactories, &c., for £600,000, is generally considered the father of the chemical manure trade. It is with extreme gratification that I cite him as the most important witness to the accuracy of my whole argument. Nothing in the way of corroboration could be more complete, full, and authoritative than the follo-\ving letter. The more important passages I have given in italics. To Dr. Adams, Glasgow. Rothamsted, St. Albans, August, 1876. Dear Sir, Pray accept my thanks for your pamphlet, which I have read with a great deal of iuterest. Since 1872 I have entirely ceased to have any interest in the commercial manufacture of manure, but for thirty years previous
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