43 
was ascertained by Vauquelin to consist of oxalic and acetic 
acids : the former may be useful in decomposing the nitrate 
of lime which is so frequently mixed with nitrate of 
potass. Nitro-muriatic acid, which the Arabs made by 
acting on sal ammoniac with nitric acid, and which 
they employed in dissolving gold, and called aqua regia, 
I have seen no notice of in the portions translated from 
Hindoo works ; but this is probably contained in the 
chapter of Susruta, describing the metallurgic arts 
for making the elixir of life. But Muriatic acid, which 
Dr. Thomson does not mention as included in Geber's work, 
the Hindoos make by mixing together common salt and 
alum, previously well dried and pounded ; they then add 
some of the above-mentioned acid liquor of the Cicer 
arietinum, and distil until the whole of the muriatic acid is 
disengaged and condensed in the receiver. 
The metals, or at least those known to all the civilized 
nations of antiquity, were also known to the Hindoos, as 
well as to the Arabs, and gold, silver, copper, iron, lead, 
tin, and mercury, are mentioned in the Amera Cosha. 
But in strictly medical works, we have also notices of 
antimony and of arsenic, with indications of their know- 
ledge of the ores of zinc. Indeed, one Sanscrit work 
is mentioned, Rasarutna Samoochayem, which treats of 
the medicines prepared with quicksilver, arsenic, and nine 
other metals (Ainsl. Mat. Med. II. p. 494) ; and though 
we have no notice of their dissolving these in the acids 
with which they were acquainted, this may, perhaps, be 
owing to those parts of their works not having yet been 
translated. But the oxides of several metals, as of 
copper, iron, lead, tin, and zinc, they were well acquainted 
with, and used medicinally : of lead, we find mention 
of both the red oxide and of litharge. With the sulphurets 
of iron, copper, antimony, mercury, and arsenic, both 
