( 760 ) 
alloy will be of great importance in the investigation of metallic alloys. 
The following method is to a large extent free from the objections 
mentioned. 
After having first determined the temperature at which crystals 
commence to deposit from the molten alloy, about 30 grams of the 
metal are introduced into a testtube of difficultly fusible glass which 
has in the centre a capillary constriction; if necessary a small plug 
of asbestos is inserted above this. The open end of the tube is now 
drawn out after which it is exhausted and sealed. The tube thus 
filled is placed in. a small electric furnace of such dimensions that 
the tube quite fills it. The furnace consists of an unglazed porcelain 
tube wound with platinum wire and is surrounded by a wider tube, 
the space between being filled in with fireclay. This furnace surrounded 
by asbestos is now placed in one of HuGersHorr’s centrifugal- 
machines such as are used for the estimation of fat in milk but 
provided with a higher rim so as to have more space at disposal. 
Two holes are bored in the lid of the centrifugalmachine to admit 
the conducting wires to the furnace. 
These wires are connected at A and B (fig. 1) with a set of 
copper rings C and D which may be screwed on to the axis of 
the centrifugalmachine. The figure gives sufficient information as 
to the working arrangement. The two copper rings are isolated by 
ebonite placed on the screw and isolated from the latter, also by 
ebonite. By attaching spring contacts to the rings C and D, an 
arrangement was obtained for admitting the current and heating the 
furnace, during the rotation. 
That the temperature during the operation remains constant could 
be ascertained by having the lid of the centrifugalmachine fitted 
with a slide valve at the place where the furnace was fixed. Before 
and after the whirling the valve was opened and the thermometer, 
inserted in a testtube filled with asbestos which was placed in the 
furnace, was read off. For temperatures up to 300° no greater 
difference than 2° has been observed before and after the whirling. 
To ascertain in how far this method can give good results, afew 
alloys which yield crystals of known composition have been subjected 
to whirling, namely Sb Sng (BEHRENS, Verslag Kon. Akad. Wetensch. 
1898 58) and CuSn (Heycock and NEVILLE Proc. Roy. Soc. 69 320). 
The experiments have, therefore, provisionally been made at tem- 
peratures which may be measured with the mercury thermometer. 
Trials with alloys of high melting points are being made in porce- 
lain tubes. 
The crystals which are obtained from an alloy of 15 °% Sb and 
