342 ACTION OF WATER ON LEADEN PIPES. 
with the aromatic productions of the land. All these will 
be found in the angle cut off by the VVadi Nogal, or in the 
limestone mountains of the Singheli and Mijjerthein tribes, 
between Ras Gulwaini and Hafoon. South of this region 
begins the Khazain (the Azenia of the ancients,) — that is, 
the sandstone mountains and the desert. Within the limits 
here pointed out, on the south-western face of the moun- 
tains, at a moderate elevation, will probably be found the 
Laurineae sought for, together with a great variety of aro- 
mata (spicy drugs,) enodia (perfumes,) and thymiamata 
(kinds of incense,) many of which are named, but not de- 
scribed by the ancients. — Pharm. Journ,,from Jlthenamm. 
ART. LXXXIV.— ACTION OF WATER ON LEADEN SERVICE 
PIPES. By E. N. Horsford, Professor of Chemistry in the Uni- 
versity of Cambridge, U. S. 
The following extracts are taken from a very important 
investigation published in the Proceedings of the American 
Academy of Arts and Sciences, for a copy of which we are 
indebted to the kindness of the author. The researches 
were undertaken at the request of the Board of Consulting 
Physicians of the city of Boston, and extend to fifty pa^es 
of closely printed letter-press. We give the author's con- 
clusions, which have more than a local interest, and the 
method which he proposes for determining small quantities 
of lead, which promises to be of considerable service in such 
investigations : — 
The waters used by man in the various forms of bever- 
age and for culinary purposes are of two classes, viz. 
1. Open waters, derived from rain-falls and. surface- 
drainings, like ponds, lakes, rivers and some springs; and 
