86 
PEOFESSOR TYNDALL ON THE ABSORPTION AND 
The quantities of ozone with which I have operated must be perfectly unmeasurable 
by ordinary means. The action of the substance is like that of olefiant gas, or boracic 
ether — bulk for bulk it might transcend either. No elementary gas that I have 
examined behaves at all like ozone. In its swing through the ether it must powerfully 
disturb the medium. If it be oxygen, it must be oxygen packed into groups of atoms, 
which encounter vast resistance in moving through the ether. I sought to decide the 
question whether it is oxygen or a compound of hydrogen in the following way. Heat 
destroys ozone. If it were oxygen only, heat would convert it into the common gas ; if 
it were the hydrogen compound which some chemists consider it to be, heat would convert 
it into oxygen plus aqueous vapour. The gas alone admitted into my tube would give 
the neutral action of oxygen, but the gas plus the aqueous vapour I hoped might give 
a sensibly greater action. I caused the dry electrolytic gas to pass through a glass tube 
heated to redness direct into the experimental tube. I afterwards introduced a drying- 
tube between the place where the gas was heated and the experimental tube. Hitherto 
I have not been able to establish with certainty a difference between the dried and 
undried gas. Previously to heating, the electrolytic oxygen had been scrupulously dried ; 
if the act of heating developed aqueous vapour, I can only say that the experimental 
means which I have employed are unable to detect it. For the present, therefore, I hold 
the belief that ozone is produced by the packing of the atoms of elementary oxygen into 
oscillating groups ; and that heating dissolves the bond of union and allows the atoms 
to swing singly, thus disqualifying them for either intercepting or generating the motion, 
which as systems they were competent to intercept and generate. 
§ 12 . 
Since these researches were commenced, an eminent experimenter has been led by his 
own inquiries in another field to enter upon the investigation of gaseous diathermancy. 
On the 7th of February of the present year (1861), Professor Magnus communicated to 
the Academy of Sciences in Berlin a memoir on the Transmission of Heat through Gases*. 
The published notices of my experiments, commencing in May 1859, had escaped his 
attention, and his work is therefore to be regarded as independent of mine. Considering 
the very different methods which we have pursued, the general agreement between us 
must be regarded as remarkable. 
The starting-point of Professor Magnus’s investigation was the interesting experiment 
of Mr. Grove, in which a platinum wire raised to whiteness by an electric current is 
suddenly cooled by an atmosphere of hydrogen. This action, which we have hitherto 
been disposed to attribute to the mobility of hydrogen, and its consequent high con- 
vective power, Professor Magnus was led to regard as an effect of conduction ; and the 
thought induced him to examine the conductibility of gases generally. The mode of 
experiment adopted led him, not I think to the establishment of gaseous conductirity, 
but to results substantially the same as those that I had previously obtained. In fact 
* PoGGEXDOEFP’s ‘ Annalen,’ reprinted in Philosophical Magazine, S. 4. vol. xxii. p. 85. 
