From August Wilhelm von Hofmann to Edward Cresy1 13 October 1860
R. College of Chemistry
Oct. 13. 1860.
My dear Sir
In reply to your note I hasten to state that I have not myself made many special experiments on the delicacy of tests.2 I must therefore quote to you such results as are known to me to have been obtained by others, stating at the same time the authority.
1 part of arsenic is detected in 64.800 parts of solution by Marsh’s test. (Taylor)3 1 part of lead in 158.400 parts of solutions by Sulphide of ammonium. (Taylor)4 1 part of iodine in 4.000.000 parts of solution by starch (Price)5
Hoping that these illustrations will suit you and Mr. Darwin, whose experiments are really of very great interest. I remain | My dear Sir | Yours very sincerely | A W. Hofmann
E. Creasy Esq.
Footnotes
Bibliography
DNB: Dictionary of national biography. Edited by Leslie Stephen and Sidney Lee. 63 vols. and 2 supplements (6 vols.). London: Smith, Elder & Co. 1885–1912. Dictionary of national biography 1912–90. Edited by H. W. C. Davis et al. 9 vols. London: Oxford University Press. 1927–96.
Taylor, Alfred Swaine. 1848. On poisons in relation to medical jurisprudence and medicine. London.
Summary
Has not himself experimented with delicacy of tests but sends several illustrations of what other authorities have done. Reference to James Marsh’s test for arsenic and that of Ashley Paston Price for iodine.
Letter details
- Letter no.
- DCP-LETT-2947B
- From
- August Wilhelm von Hofmann
- To
- Edward Cresy, Jr
- Source of text
- DAR 58.1: 4
- Physical description
- ALS 2pp
Please cite as
Darwin Correspondence Project, “Letter no. 2947B,” accessed on 24 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-2947B.xml
Also published in The Correspondence of Charles Darwin, vol. 8