214 
NATURE 
[¥uly 14, 1870 
has been allowed to evaporate, as tested by the smell. The 
solution is also carefully filtered before use, and diluted to a small 
extent. After from three to ten minutes or more in the carmine 
solution, the section is placed in distilled water and thoroughly 
washed for some time by blowing into the water with a small 
pipette. From this the section is removed momentarily to a 
watchglass containing distilled water and two drops of acetic 
acid, and then is placed in absolute alcohol. The water is thus 
removed, and in five or ten minutes the section may be placed in oil 
of cloves, which renders it very transparent. From this it is re- 
moved to the glass slip, and is mounted in a solution of gum 
damara in turpentine, such as is sold by artist’s colourmen. At 
any stage in this process we can proceed back again by the same 
steps, ammonia being used in place of acetic acid, and re-stain, 
re-wash, or re-acidify as the case may be. If the staining 1s care- 
fully managed and the subsequent washing a thorough one, most 
cellular structures are very beautifully and clearly brought out. 
Where rapidity is desired, and for the purpose of inspecting a 
specimen, it may be simply mounted in glycerine after the 
staining, The process above described is that of Gerlach and 
Stieda, and is preferred to any other by some observers of great 
experience. Thus Dr. Meynert, of the lunatic asylum at Vienna, 
who is throughout Germany regarded as the great authority on 
the histology of the brain, uses this method for mounting his sec- 
tions of cerebrum, cerebellum, &c. It is very convenient to have 
little glass dishes with covers for each of the above-mentioned re- 
agents, so that the sections may be passed from one to the other 
and left covered up, if desired, for a day or two—the waste of 
re-agents involved in filling watch-glasses each time they are 
required being also avoided. If preparations have been preserved 
in chromic acid, they must be very well washed before staining, 
and very often cannot be made to stain well at all. Various 
methods are useful in various cases, but, as one of great general 
use, the carmine staining and oil of cloves clearing may be 
strongly recommended. Staining tissues with nitrate of silver, 
chloride of gold, and with bile-pigment are most important aids 
to the histologist, the merits of which have been recently much 
discussed, and of which we shall have a word to say from 
experience. 
Glycerine Felly.—This composition, which has been lately 
introduced, melts at a lower temperature than Deane’s medium, 
and has a greater clearing action on the objects mounted in it. 
A small piece of the jelly put on a glass slip and warmed, soon 
liquefies, and is ready to receive any object, after which the cover 
is directly applied. For objects which do not require any great 
amount of “clearing,” it is a most useful medium, Insects, 
worms, small crustacea, &c., may be mounted in this way 
excellently, E. Ray LANKESTER 
METEOROLOGY OF FUNE 1870 
I BEG to send you a few particulars of the weather of 
the past month (which was characterised by unusual 
atmospheric phenomena), deduced from daily observations 
with standard instruments, the place of observation being 
in latitude 51° 27’ N., longitude 0° 18’ W., height above 
sea level 64 feet. 
The barometrical readings have been corrected for capil- 
larity, index error determined by comparison at the Royal 
Observatory, Greenwich, and certified by James Glaisher, 
Esq., F.R.S., and reduced to 32° Fahr. and mean sea level. 
The thermometrical readings have been corrected for 
index error determined by comparison at the Kew Obser- 
vatory of the British Association. 
Time of observation, thermometer 7" 45™ A.M., baro- 
meter 8 o™ A.M., wind direction 8" 30™ A,M., daily (ap- 
proximate). 
The following are the calculated monthly means, &c. 
Mean height of the barometer (corrected) . 30°135 in. 
Highest observed reading . . . . «© «+ 30°551 in. 
Lowest observed reading . . . . . + » 29°747 in. 
Wonthlyrante =) opis ee ue eles) bs) en OssO4uans 
Mean temp. air (7"45™A.M.). . . . - 60°8° 
i = Pofevaporation’ Pees 6) ee Shih 
» Ofdew point. . = | 50°6° 
6 Pores 
Relative humidity (dry air=o, saturation=100) 70 
NMeanvotthemaxinral pes pep i) smitenisen es | baie 
Mean ofthe minima . . . . : «5 « = « 
Mean diurnal range of temperature . . . . 
ae Highest reading (June 22) . . 91°4° 
ES Lowest reading (June 6) . . . 41°6° 
Monthly range of temperature . Agee 
Mean estimated force of wind (Ooto6) . . .  1°5 
‘Total rainttallgeriteyys «|. ys) 2 <2 <s\biew leet Maen OLS O 7aeltle 
Days ‘onswhichixamifell . 2 2.2) Ge 
Evaporationon22days. . .. +. ». ». . 37652 in. 
Mean intensity of ozone (24h). . . ee 
Af Ee 5 
*.* Sun at greatest meridional altitude (year) or greatest N.D. 
June 21st. 
A lunar halo (or portion of a circle) was observed on 
June 9 shortly after 10" P.M. (or 10" astronomical time). 
Its estimated extent was 270° of a circle whose diameter 
was 60°, Estimated altitude of the moon at time of obser- 
vation, 35°. 
A thunderstorm occurred on the 16th, with very vivid 
lightning, yielding 0°355 inch of rain, which was equivalent 
to 7987°5 gallons, 1288°65 cubic feet, or 35°9 tons per acre, 
assuming the rainfall to be equally distributed, which 
may be done with some degree of truth, as the amount 
measured at the Kew Observatory, one mile distant, agrees 
with mine to the second decimal. 
The atmosphere was moderately charged with moisture 
during the month, which must have been an assistance to 
vegetation in spite of the excessive drought. 
The rainfall during this month was 0'558 inch less than 
that registered during the corresponding period last year. 
Wind directions in the lower regions of the atmosphere 
were observed on 12 out of 16 points, the prevailing direc- 
tions being between W. and S.W. points. 
Richmond, Surrey, July 7 JOHN J. HALL 
THE ROTUNDITY OF THE BARTS 
“TARALLAX” is not dead yet. His backer, Mr. John 
Hampden, has again brought his sophisms and his 
misstatements before the public in the form of a periodical 
called the Avmourer, which has already had one period 
of existence, having been discontinued about four years 
since, “amidst the regrets of hundreds of its readers,” 
as the editor asserts. When Mr. Hampden speaks of the 
recent experiment by which the falsity of “ Parallax’s” 
views was exposed, as “the Bedford Canal swindle,” of 
Mr. Wallace’s victory as having been obtained by “ Scotch 
knavery and cunning,” and of the conduct of the editor 
of the #7e/d as umpire as having been “ false, unfair, and 
fraudulent,” we may well leave these charges to be replied 
to by these gentlemen themselves, or by the law. As, 
however, “ Parallax” repeats unblushingly his assertion 
that he has for years propounded his views by lectures in 
various parts of the country without their having been 
once refuted, we may call to his remembrance a cir- 
cumstance which he has probably found it convenient to 
forget. During the recent experiments at the Bedford 
Level, “ Parallax” carefully concealed the fact that the 
very same test had been previously applied. In the year 
1856, however, after a lecture by “ Parallax,” at Norwich, 
two gentlemen challenged him to an experimental proof 
of his views. He accepted the challenge and was invited 
to witness the experiment, which invitation, however, he 
did not respond to, but prudently left the town in the 
interim. The nature and result of the experiment are de- 
tailed in a printed slip which was inserted at the time in 
the local papers, and a copy of which we append :— 
Cory OF AGREEMENT.—We, the undersigned, ‘‘ Parallax,” 
of No. 61, Upper North Place, Gray’s Inn Road, London, on 
the one side, and John Weir, of No. 14, Suffolk Street, Union 
Place, Norwich, and Charles William Millard, of Prince’s Street, 
Norwich, on the other side, having different opinions as to 
whether the Earth be a Plane or a Globe, agree to test the accu- 
racy of our respective opinions in the following manner, that is 
to say, to place four flags in a straight line, intersecting the 
River Yare between Strumpshaw or Bradestone and Norton, for 
a space of not less than four miles, or six miles if possible. 
The flags to be at the same height above the water except the 
