To Thomas Archer Hirst

My dear Boys

I believe Fresenius¹ does not contain a table of the elements and without them he would be unintelligible. I have copied a list with the symbols used to express them. Always the initial letter or some two letters which form the chief part of the sound in pronouncing the name – you will find these symbols in combination in Fresenius – for instance Soda is composed of one atom of Natron or Sodium (the names for the same substance) and one of oxygen and it is written Na O. Alumina is composed of two of aluminum and 3 of oxygen and is therefore written Al O and so of the rest. The elements are divided into two grand classes the metals and the metalloids – those marked with the X are metalloids the rest are metals. They are distinguished by the latter possessing that lustre which we call metallic, while the former possess it not, but more particularity by the fact that the metals are conductors of electricity and the metalloids not. A metalloid combining with oxygen usually forms what is called an acid from its taste – for instance sulphuric acid is expressed by SO one of sulphur and 3 of oxygen – nitric acid by NO one of nitrogen to 5 of oxygen, and so on. There may be and are other acids formed with nitrogen and oxygen, and with sulphur and oxygen than nitric acid and sulphuric acid but the termination -ie always indicates that acid which has the greatest amount of oxygen in its composition. Do not let the number of these elements frighten you many of them are very rare and will never trouble you – you must read quickly on until you come to the groups – you will meet the term 1st. group Potass, Soda, Ammonia, the latter with the symbol NH or NH O I forget which, both are right in a certain sense. Here you must halt and must verify every statement he makes with regard to every substance in the six groups – for instance he says the salts of soda² are soluble in water, take a little of the carbonate and prove the truth of this. You must have a little bottle with a thick neck in which you must put a cork and through the cork insert a little candlewick fill the bottle with naptha and this is the spirit lamp you must have. You will also want a blowpipe which any druggist will tell you where to procure. I use the term salts which I must explain – The metals unite with oxygen thus forming oxides or ‘bases’ – thus iron rust is simply formed by the oxygen of the atmosphere uniting with the outer particles of the iron and is written FO. In the same sodium unites with oxygen to form soda NO when an acid unites chemically with one of these bases the product is called a salt. Thus carbonate of soda is composed of carbonic acid CO and soda NO and is written NO, CO. And now I shall bid you goodbye for the present.

Ever yours affectionate | Tyndall

Aluminum	Al	Didynamin		(Mercury)
(Antimony)		Fluorine X	F	(Hydrargyrum)	H
(Stibium)	S	Glucinum	Gl	Molybrenum	M
Arsenic X	H	(Gold)		Nickel	N
Barium	B	(Aurum)	A	Nitrogen	N
Bismuth	B	Hydrogen X	F	Osmium	O
Boron X	B	Iodine X	I	Oxygen X	O
Bromine X	B	Iridium	I	Palladium	P
Cadmium	C	(Iron)		Phosphorus X	PH
Calcium	C	(Ferrum)	F	Platinum	P
Carbon X	C	Lanthanum	L	(Potassum)
Cerium	C	Lead		(Kalium)	K
Chlorine X	C	Plumbean	P	Rhodium	R
Cobalt	CO	Lithium	L	Ruthenium	R
Chromium	C	Magnesium	M	Selenium X	S
(Copper)		Manganese	M	Silicium X	S
(Cuprum)	C
(Silver)		Tellurium X	T
(Argentum)	A	Thorium	Th
(Sodium)		(Tin Stannum)	S
(Natrium)	N	Titanium	T
Strontium	S	Wolfram	W
Sulphur X	S	Uranium	U
Tantalum	T			Vanadium	V
				Yttrium	Y
				Zinc	Zn
				Zirconium	Z3

RI MS JT/1/HTYP/19

LT Transcript Only