so 
A weak solution of Iodine, such as Mohr’s standard solu- 
tion, acts readily upon the Sulphited Phosphate of Lime, as 
represented by the formula 
3CaO, P0 5 , S0 2 , 2HO + I - CaO, 2HG, P0 5 + CaO, S0 3 + Cal. 
The colour of the Iodine disappears as long as there is sub- 
stance left undissolved. This is a convenient method for 
estimating the Sulphurous Acid of the compound, but as 
the last portions are only slowly acted upon by the Iodine, 
it is advisable, in order to save time, to add a drop of Hydro- 
chloric Acid when the Iodine begins to disappear slowly. 
It does not interfere with the accuracy of the experiment. 
The Sulphited Phosphate of Lime, exposed to an atmos- 
phere containing Ammonia, rapidly absorbs the latter; but 
at the same time an equivalent quantity of Sulphurous 
Acid seems to be oxidised. A sample of the substance was 
placed under a glass shade, with pieces of Carbonate of Am- 
monia and water for four weeks, and subsequently over Sul- 
phuric Acid for two days, and yielded by analysis the fol- 
lowing results: 
Lime 39-08 per cent. 
Sulphurous Acid ... 2-50 „ 
Ammonia 5 “60 ,, 
The new Sulphite possesses remarkable antiseptic and 
disinfecting powers, and on this account will command a 
general interest. The efficacy of Sulphurous Acid as a dis- 
infectant is well known; it would be more appreciated if it 
could be conveniently applied. The aqueous solution is 
expensive by transport, it is very changeable, and in many 
cases it is unavailable on account of its pungent smell; 
whilst for medical purposes it can only be used in excep- 
tional cases, in consequence of its irritating action. The 
Sulphites are still more changeable. Exposed to the air they 
are acted upon by Carbonic Acid and b}^ Oxygen, and when 
mixed with decaying organic matter for disinfecting pur- 
poses they very often increase the mischief, and sometimes 
