18 
FACTS AND OBSERVATIONS. 
Dover Castle, and, pending the completion of the necessary 
drainage works, earth conservancy has been introduced. A 
series of simple wooden boxes have been constructed with a 
shoot and hopper, which delivers its earth as soon as the per¬ 
son rises from the seat. "When first introduced, it was found 
necessary to enter into a contract with a neighbouring farmer 
to bring in dry earth and remove the refuse. Upon the 
termination of that contract, the offer was made that he 
should do the work for nothing, the officer in charge having 
observed the splendid crops which had been, obtained from 
the application of the manure. This offer was embraced, and 
the solid refuse of the fort (which contains over two hundred 
men), and a considerable proportion of the urine also, are 
removed by means of dried earth, without any cost to the 
government. It would appear that the refuse soil and weeds 
are collected by the farmer and burned. The mass is then 
passed through a sieve and conveyed to a covered part of the 
fort. The hoppers are filled daily, and the refuse is removed 
at regular intervals. One of the seats is situated in a close 
corridor behind casemates, in immediate proximity to the 
officers^ apartments, and there is absolutely no smell. Those 
for the men are temporarily placed in a very confined situ¬ 
ation, and we have every reason to believe that their action 
has been equally successful. It may be of interest to know 
that the seats, boxes, and hoppers were made by the soldiers 
at a cost of four shillings each.— Lancet^ Oct. 31, 1868. 
Thymic Acid as a Disinfectant. —M. Bouilhon com¬ 
municates some observations on a substance which may be 
employed as a disinfectant, and possessing the recommenda¬ 
tion of an agreeable smell resembling that of thyme. It is, 
indeed, extracted from essence of thyme, and is called thymic 
acid. It enjoys the valuable property of combining with skin 
and animal tissues, thus rendering them incapable of putre¬ 
faction. In a concentrated state it has an acrid and caustic 
taste, but, when much diluted, it produces on the tongue the 
agreeable sensation caused by peppermint. M. Bouilhon 
has found by experiment that it may be substituted for 
phenic acid and creosote in every case in which they are used 
as therapeutic agents.— Standard. 
Instrument for Measuring the Velocity of Pro¬ 
jectiles. — As a proof of the remarkable accuracy now 
attained in the manufacture of philosophical instruments, a 
chronograph, invented by Captain Noble, R.A., for mea¬ 
suring the velocity of projectiles within the bore of a gun, 
and lately used by the Ordnance Select Committee, registers 
the hundred-thousandth of a second,— Ibid. 
