312 Scientific Intelligence. [Ocr. 
I flatter myself that your Correspondent Mr. L. will now perceive 
that he was rather too hasty in concluding that “ all numbers have 
four imaginary cube roots.” And further, as it appears that it was 
not impossible or imaginary quantities which led ‘¢ to such difference 
of sentiment” in this case, Mr. L. will not now perhaps think it 
<¢ wise to abandon them altogether,” particularly as it is known that 
in some cases they lead very readily to results which are very trouble- 
some to obtain by any other method yet discovered. 
Iam, Sir, your obedient servant, 
Newcastle, Aug. 12, 1815. H. ATKINSON. 
P.S. In my letter of June 16, p. 73, line 6 from the top, for 
—— 
: Ea cme: Me eB ‘ 
VAT 7 7 oy read S+4/- Pin and line 14 
——— 
from the top, for VY 36L V7 7384 = 7 64 Me 8, read 
V7 36+ Vf 784 =v GLory 8. 
VII. Test of Iodine. 
Stromeyer has announced that starch is so delicate a test of iodine 
when in an uncombined state, that it assumes a perceptible blue 
tinge when no more than ,,),5;th part of iodine is present in the 
liquid examined. I have not tried this test myself; but suppose 
that in most cases it will be requisite to add an acid to the liquid in 
order to disengage the iodine from its combination. The blue com- 
pound of iodine and starch was first made known to chemists by 
MM. Colin and Gaultier de Claubry, 
VIII, Rapid Intercourse through Great Britain. 
The rapid intercourse which at present exists between every part 
of Great Britain and the eapital must have struck every person who 
has travelled through this country. We meet with no marked dis- 
tinctions in the dress or manners of the different provinces. The 
fashions in the most remote parts of the country are quite the same 
as in London. This rapid intereourse began during the seven years, 
war when Britain first became a great commercial country, and it 
has been increasing ever since. I[t is owing in a great measure to 
the goodness of the roads, which have been made over the whole of 
Great Britain, and to the navigable canals, which have in some 
measure united the most distant manufacturing towns with each 
other and with the capital, Before the year 1760, the inland towns 
of Great Britain, such as Manchester, Leeds, Halifax, &e. chiefly 
carried on their business through the medium of travelling pedlars, 
and afterwards on pack-horses. The journey in this manner from 
Manchester to London occupied a fortnight ; and it was not unusual 
for a trader going for the first time on this expedition to take the 
precaution of making his will. At present the stage coaches perform 
the journey in about a day and an half. ,' 
In the year 1725 there was not a cart in the whole county of Mid 
Lothian. The farmers in the neighbourhood of Dalkeith carried 
