FACTS AND OBSERVATIONS. 
753 
sesquioxide of iron/^ The author concluded by expressing 
the hypothesis that the iron is reduced by the temperature 
to a colloidal condition, which is kept in solution either in 
hydrochloric acid or in sesquichloride of iron.— L’lnstitut. 
A Phosphorus Holder. —A suggestion has been made 
by Mr. E. Kern an, in a letter to the Chemical News, June 
11th, which, we doubt not, may be found useful by lecturers 
and others engaged in demonstration:—A few inches of lead 
tube ^-in. bore, is contracted to an open cone, at one end. 
As much phosphorus as one may choose is put into the cone 
of the tube; the phosphorus is made to project slightly from 
the cone; the upper part of the tube is filled with water, 
and corked. Thus is had a phosphorous crayon’^ perfectly 
safe in the hand for luminous writings, &c. To put in the 
phosphorus, as much as may be required is melted in a 
conical glass, or test-tube, the cone of which is larger than 
that of the lead tube. This is put standing in the melted 
phosphorus, which fills the cone and tube to its own outside 
level. When cold, there is a nice projecting crayon, from 
the form of the glass. Any phosphorus outside the lead 
tube may be melted oflp. To renew the writing point, a test- 
tube, conical below, is fitted to the cone of the lead; the 
whole held in warm water for a minute, as much phosphorus 
flows out as forms a new point.— Ibid. 
The Desiccation of Rotifers. —The Iroceedings of the 
Literary and Philosophical Society contain a report by Pro¬ 
fessor Williamson on some observations on this questionable 
phenomenon by Lord Osborne. Professor Williamson ex¬ 
hibited some small glass tanks or Rotiferous aquaria, some of 
which had been prepared by Lord S. G. Osborne, which 
had been dried up again and again. One of these, in a dry 
state as it had been for five months, was moistened by the 
addition of a little water, and in five minutes the animals 
were in full activity, looking thin and hungry, but perfectly 
vigorous. The experiments of Lord S. G. Osborne confirm 
the statements of Spallanzani, that these Rotifers may be 
dried up for years without vitality being destroyed. Tanks 
for the preservation and examination of these objects are 
readily made by joining two ordinary microscopic glasses on 
three sides by means of electric cement, and then stocked by 
the introduction of a little Rotiferous dust. In such tanks 
they multiply rapidly, the occasional addition of a few drops 
of water to counteract evaporation being all that is needed 
for their preservation.— Ibid. 
