Botany and Zoology. 441 
per cent will remain in relation to the pyrites, or about *10 in relation 
to the manufactured oil of vitriol. Now suppose the superphosphate 
made from this acid to contain 20 percent of it as a constituent, and 
that 3 cwt. are used as a dressing per acre, there will be added to this 
acre ‘07 of a pound of arsenic, and this is to be distributed among from 
_ 20 to 25 tons of roots, giving a percentage infinitely small, and in my 
_ opinion relieving us from the necessity of the smallest anxiety on the 
subj , however, even this quantity is objectionable, the use of the 
_ Belgian pyrites, in which I have never found a trace of arsenic, would 
obviate all difficulty.” A, G. 
8. Botanical Necrology for the year 1859.—The following are the prin- 
: years. was su 
* his professorship by his son ©, A. Agardh, the distinguished algologist. 
_ Arthur Henfrey, Professor of Botany in King’s College, London, The 
4 of research and in his knowledge of the literature of the subject, oe 
a 4 that of the Germans, he had no rival in Great Britain, and his 
fi : 
Dr. Thomas Horsfield, born in Pennsylvania, after completing his 
medical studies in Philadelphia he passed sixteen years in Java and the 
adjacent islands, in the service of the government, devoting much of his 
___Bme to botanical and zoological researches ; and the long remainder in a 
: ie position at the India House, in London, A selection only of 
: botanical collections was published by Mr. Brown and Mr. Bennett, 
_ under the title of Plante Javanice Rariores, ete—a most important 
a ee Dr. Horsfield died, on the 14th of July last, in the 86th year of 
ALS. Lejeune, a venerable Belgian botanist, died at Verviers, at the 
ae’ Close of the year 1858, in the 80th year of his age. FH tes 
. he « as Nuttall, born at Settle, in the West Riding of Yorkshire, in 
_ /8 year 1784, may yet be reckoned as one of our own American botan- 
its, since he came to the United States when only 22 years of age, and 
ND SERIES, Vou. XXIX, No, 87.—MAY, 1860. ; 
56 
