288 On preserving Potatoes for Sea Store or Exportation. 
of Bennet is an instrument not to be depended on without ac- 
guaintance svith a principle of electricity which I have developed, 
and which in a work soon to appear will be shown to have 
misled mauy able investigators. Any electrometer on the same 
principle, whether pith- ‘balls or gold-leaf, is lable to the same 
objection. In the counter-experiments this error has not been 
guarded against.” Mr. Donovan, not satisfied with the defence 
he has made for his experiments, here turns short round upon 
the innocent electrometers, and tells us they cannot be depended 
on; and yet, I believe that any of them may be more safely de- 
pended on than the sulphur on which he has been pleased to 
place his whole reliance. However, if he continues obstinate, 
and is determined to reject their testimony, [ have no objection 
to his so doing; for, on re-perusing my paper, he will find that 
the excited glass tube by always steadily repelling the balls con- 
nected with the overcharged surface of the jar, and that the ex- 
cited wax by always steadily repelling those connected with the 
undercharged surface, afford ample evidence in my favour in- 
dependently of the testimony of the reprobated electrometers. 
Equally steady in its testimony was the small Leyden phial 
I employed, and the electrometers were only used to ascertain 
the electric changes which took place in the excited electrics: 
hence Mr. Donovan’s attack upon the electrometers avails him 
nothing, and there is little truth in the remark that ‘¢ in the 
counter-experiments this error has not been guarded against ;”’ 
for, had the electrometers been as treacherous as he would wish 
us to believe, and had I been as much deceived by employing 
them in my experiments as he was by not employing them in 
his, my errors would still have had no relation to the electrical 
states of the phial; because they were ascertained by the faithful 
and unimpeached testimony of the other instruments. 
I am, sir, 
Your obligetl servant, 
Ilereford, April 15, 1816. Tsomas How.py. 
LX. On preserving Potatoes for Sea Store or Exportation, 
by Mr. Caries WuirLow, of Canada; and on preserving 
Carrots, ly H. B. Way, Esq. of Bridport Harbour*. 
rn New York Coffee-Flouse, Feb. 12, 1815. 
Sir, — i] HE usual mode at present practised for endeavouring 
to preserve potatoes, is to leave them after digging exposed to 
the sun and air until they are dry: this exposure generally 
* From Transactions of ihe Sociely for the Encouragement of Arts, Manu- 
Suctures and Commerce, vol. xxxiil. for 1815.—The silver medal of the So- 
ciety was voted for this communication. 
causes 
