The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1879-10-25

cal action be made into glass or crystalline srsenic.
AZ either form Is taken in aud sntirey sbsorhed. 80
that AZ ceased 10 exist In it, original chemical eond
ton. and the chemist obtains this solution. he
fonic."
Professor Dana detailed AZ considerable length the
PROCESS OF arsenic mauufacfure al A@st~toch, ahd
especially In ia bearing on the formation 81 crystals.
anu SAID that in the farnaccs the laracr crystals
Recess was taken al eleven o'olock. aud upon TO
stunning the proceedings Mr.. Mafrons inquired.
rro,e.sor: may ask whom you have been talking
Certainly. sir. conversed with Professor Sill
man OF Yale College. and one Of the counsel for the
state And as accidental conse usnoe % the con-
versations wish TO change nay tcstin ony-t0 cor
rect chance slip OF the tongue. have said that
the larger crystals would be found nearer the IRE IN
the furnace. whereas should have said farthest
from it,"
''who told you OF your crrory'
zone or the states counsel made a romark from
which saw at once that had made an accidental
error"
Microscopic slides of the scoigrove'' and -barn''
arsenies were produced. also a scrupie OF arsenic
from the mill at Tavistock visited by witness. an
were carefully and with wise air examined by tho
Jurynien, who could gioan nothing very valuable
from examining slips of glass with only smoke
circles visible thereon. One juryman. with much
labored and comical squirting or tho eye tried ~
with tweve-power microscope. Professor Dana
was also required to examine the slides through am
Instrument OF similar power. and was asked what
al observe an indstinct difference, but with so
small glass to assist the eye cannot describe any
ARSENIC MANUFACTURE
In reply to extended series OF questions Profess
sor Dana described his Observations of the forma-
ton OF CRYSTALS III arsenic manufacture ut Tavistock
and expressed his belief that there IL regular gra-
dation in the size of the crystals in all the samples
he had seen up to certain point--from powder up
to particles whose forms disting by the
unassisted eye. The process of grinding also
described. ''The arsenic" he said sis shoveled up
from the floor like dust, and into u hopper whence
it passes between the grinding stones. between
three and four feet in diameter. As the stones are
or mart will slt.al1v hocn
larger, OF course.
When tho court opened for the afternoon session
the jury sat staring out of tho windows ut lively
snow squall which was prevailing. Perhaps appre-
bending being showed up ON the railroads, one OF
the jurymen asked the Court Cor earlier adjourn
ment than usual adding, "Some OF us have got to
foot it across country from Seymour to Oxford"
Professor Dana; resuming. was asked:-
"Where will the largest crystals OF arsenic be
found in the series OF chambers in manufacturing
arsenio?'
..rhe chambers have so large a part of their sur
face exposed to the outside air that would tend to
prevent the considerable heat OF the chamber to
such q degree as would not otherwise be the case.
The vapors are the hottest nearest the furnace Of
course, and they gradually cool they pass through
the chamber and connecting tubes. The difference
the chamber would therefore be greatest the
furnace. This great difference Of temperature
would. think. result in the more rapid cooling of
the vapors themselves, and the largest crystals
would be the furthest away
"what becomes of the vApors that do not crystal
lie even on reaching the last chamber?'
"In the Tavistock works they passed into room
where water was falling. and this removed tho
greater part of the arsenic"
''What is the angle OF the chambers as to the
furnacc?'
"My impression is"
81 don't want your impression; want the fact"
"But object to having my Impressions go to the
world as direct statements"
Never mind your objections. What is that angler"
Professor Dana hesitated moment and then tho
faintest CLEAN of merriment lighted his eyes. as
taking renholdcr and holding it up. he said:-
Well it might be this angle and It might be that
And he first raised the penholder to angle Of
twenty degrees and then suddenly to eighty.
This was greeted with general laughter and spec
tator remarked THAT Dana 3 hard boy corner.
They'll get enough Of him before they get through"
The interrogatories to the chambers and the heat
and capitalization therein continued LENGTH
and were largely a repetition of Professor Dana's
testimony in chief. The subject of grinding was
ommercia arsencs there is ninety-nve Der cent of
crystals and i'll others only ten; in ground lump
arsenic crystals. In the former the crystals come
from the furnaces so small that they are not
'Name the conditions affecting the crystals of
arsenic?
81 do not know all, but I will state those do
know. First, the temperature at which the vapor
cools or the rapidity with which that original tenn
perature is reduced; second, the density of the
vapor; third. the absence or presence in different
degrees of foreign matter in the vapor; fourth,
grow by continued additions of particles as the
crystals are attached to some exposed surface.
Those are the conditions. believe, governing tho
formation of arsenic crystals The conditions, how
ever, may vary to some cxtept"
TEST QUESTION.
eff you had ten samples of arsenic given you to
examine would you be willing to risk your profess
sional reputation determining whethor they came
from the same or different packages. We will fur
nish them, and will do without tampering or
trickery?' %
Mr.. Harrison flor the State)-That's fair ques-
ton. Professor. Answer 1t.
al should be perfectly confident Of being able to
decide this point to some of the samples Of the
ten. understand ten different samples taken from
ten shops at random"
Mir. watrous-You not to know whether they