August 2G, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
167 
tthis process its volume will steadily. diminish as the ; other physical properties of the carbonic acid which has 
pressure augments, and no sudden diminution of vo- collapsed into the smaller volume, and of the carbonic 
flume, without the application of external pressure, will acid not yet altered. There is no difficulty here, there- 
'occur at any stage of it. When the full pressure has fore, in distinguishing between the liquid and the gas. 
■'been applied, let the temperature be allowed to fall till; But in other cases the distinction cannot be made ; and 
'the carbonic acid has reached the ordinary temperature j under many of the conditions I have described, it would 
of the atmosphere. During the whole of this operation be vain to attempt to assign carbonic acid to the liquid 
no breach of continuity has occurred. It begins with a , rather than the gaseous state. Carbonic acid, at the 
.■gas, and by a series of gradual changes, presenting 
mo where any abrupt alteration of volume or sudden evo¬ 
lution of heat, it ends with a liquid. The closest obser¬ 
vation fails to discover anywhere indications of a change 
temperature of 3mo 0 , and under a pressure of 108 atmo¬ 
spheres, is reduced to of the volume it occupied 
under a pressui - e of one atmosphere; but if any one ask 
whether it is now in the gaseous or liquid state, the 
of condition in the carbonic acid, or evidence, at any ; question does not, I believe, admit of a positive reply 
period of the process, of part of it being in one physical Carbonic acid at 35'5°, and under 108 atmospheres of 
state and part in another. That the gas has actually | pressure, stands nearly midway between the gas and the 
changed into a liquid would, indeed, never have been liquid; and we have no valid grounds for assigning it to 
■-suspected, had it not shown itself to be so changed by 
•entering into ebullition on the- removal of the pressure. 
For convenience, this process has been divided into two 
•stages, the compression of the carbonic acid, and its sub- 
the one form of matter any more than to the other. 
The same observation would apply with even greater 
force to the state in which carbonic acid exists at higher 
temperatures and under greater pressures than those 
sequent cooling ; but these operations might have been just mentioned. In short, the passage under great pres 
performed simultaneously, if care were taken so to sures from the liquid to the gaseous state may be effected 
arrange the application of the pressure and the rate of 
cooling, that the pressure should not be less than 76 
atmospheres when the carbonic acid had cooled to 31°. 
by the application of heat without break or breach of 
continuity. That a marked change in the physical pro¬ 
perties of the substance occurs during this process is no 
We are now prepared for the considexation of the fol- j objection to its being continuous. If mercury as a liquid 
lowing important question. What is the condition of; is opaque and as a gas is transparent, the red. and trans- 
'-carbonic acid when it passes, at temperatures above 31°, lucent bromine, on the other hand, when heated above 
from the gaseous state down to the volume of the liquid, | the critical point, becomes so opaque as almost to re- 
without giving evidence at any part of the process of semble a mass of resin. Fi'ankland has shown that the 
liquefaction having occurred ? Does it continue in the flame of hydrogen becomes continuous when the gas is 
-gaseous state, or does it liquefy, or have we to deal with burned under a pressure of 20 atmospheres, and these 
• a new condition of matter? If the experiment were experiments have been since extended by the same 
made at 100°, or at a higher temperature, when all indica- 
'tions of a fall had disappeared, the probable answer 
which would be given to this question is that the gas 
■preseiwes its gaseous condition dui’ing the compression ; 
•■and few would hesitate to declare this statement to bo 
able chemist and Lockyer. We must not, however, 
suppose that one intermediate state exists between 
liquid and gas; on the contrary, an indefinite succession 
of inteimediato states may truly be said to connect the 
liquid proper and the gas proper; in other words, the 
• 1 * TTTl._J_T__ nr* 
true if the pressure were applied to such gases as hydro- passage is continuous. When the ci’itical point is at 
gen or nitrogen. On the other hand, when the experiment tained, tho density of the liquid and gas becomes the 
is made with carbonic acid at temperatures a little above | same, and the tube is filled with homogeneous matter. 
-31°, the great fall ■which occurs at one period of the pro- ! As regards the question of the continuity of the solid 
-cess would lead to the conjecture that liquefaction had ! and liquid states, it would be necessary, in order to 
actually taken place, although optical tests carefully ap- , establish this continuity, to obtain, by the combined 
THE HONEY TRADE. 
BY r. L. SIMMONDS. 
tional pressure being always required for a further dimi- ; yond any which can be reached in transparent tubes ; 
nution of volume is opposed to the known laws which but it may be possible to show by experiment that the 
-hold in the change of bodies from the gaseous to the j solid and liquid can be made to approach to the required 
liquid state. Besides, the higher the temperature at conditions, 
which the gas is compressed, the less the fall becomes, 
.and at last it disappears. 
The answer to the foregoing question, according to 
Avliat appears to me to be the ti*ue interpretation of the 
-experiments already described, is to be found in the close 
and intimate relations which subsist between the gaseous 
•and liquid states of matter. The ordinary gaseous and 
■ordinary liquid states are, in short, only widely sepa¬ 
rated forms of the same condition of matter, and may be 
made to pass into one another by a sei’ies of giadations 
%so gentle that the passage shall nowhere present any in¬ 
terruption or breach of continuity. Fi’om carbonic acid 
as a perfect gas to carbonic acid as a perfect liquid, the 
^transition we have seen may be accomplished by a con¬ 
tinuous pi'ocess, and the gas and liquid, arc only distant 
•stages of a long series of continuous physical changes. 
Under certain conditions of tempexuture and pressure, 
•carbonic acid finds itself, it is true, in what may be 
described as a state of instability, and suddenly passes, 
with evolution of heat, and without application of addi¬ 
tional pressure or change of temperature, to the volume, 
'which by the continuous pi’ocess can only be reached 
through a long and circuitous route. In tho abrupt 1867 
change which here occurs, a marked difference is ex- 1868 
habited, while the process is going on, in the optical and 1869 
The following facts connected with the honey trade, 
showing the great commercial importance of this product 
of the bee in various countries, are taken from the Jour¬ 
nal of Applied Science. 
Mr. Braithwaite Poole, some years ago, in his work 
on the ‘ Statistics of British Commerce,’ estimated, after 
careful inquiries of the quantities transported over the 
kingdom (for which he had peculiar facilities), that the 
pi'oduction of honey here amounted to 2000 tons, which 
he valued at £80,000. The annexed figures will give an 
idea of the foreign imports. The average of the four 
years ending 1858 was 3712 cwt., ancx the last three 
years for which we have official rctui'ns give the follow - 
mg: 
Quantity. 
Cwt. 
5,663 
6,671 
, 14,820 
Value. 
£8,681 
10,077 
22,570 
