Radiation of Heat by Gaseous Matter. 347 



Fearing that the more active perfumes might possibly preju- 

 dice the action of the more feeble ones which succeeded them, I 

 made a series of experiments with the following essences, and 

 obtained the results recorded : — 



Camomile flowers 87 



Spikenard 355 



Aniseed 372 



After this enormous effect I repeated the experiment with 

 bergamot, and found its action to be exactly the same as that 

 recorded in the Table. 



I made a few experiments on musk, but obtained different 

 results with it at different times. On the 16th of October I 

 obtained some fresh musk from the perfumer's, placed it in a 

 small glass tube, and carried dry air over it into the experimental 

 tube. The first experiment gave me an absorption of 74, the air 

 which carried the perfume being unity. A second experiment, 

 in which the air was admitted more quickly, the absorption 

 was 72. 



It would be idle to speculate upon the quantity of matter 

 which produced this result. The stories regarding the un- 

 wasting character of this substance are well known ; suffice it to 

 say that a quantity of its odour carried into the tube by a cur- 

 rent of air of a minute's duration, produced an effect seventy-two 

 times that of the air which carried it. Long-continued pumping 

 failed to cleanse the tube and pasages of the musk. It cannot 

 be volatile, for an amount of ether vapour which produces a far 

 greater action is speedily cleared away, while the cocks and con- 

 necting-pieces of the air-pump had to be boiled in a solution of 

 soda before they were fit for use after the experiments with this 

 substance. 



Two perfectly concurrent experiments with ordinary cinnamon, 

 in which fragments of the substance were placed in a tube and 

 had dry air passed over them, gave an absorption of 53. 



Several kinds of tea, treated in the same manner, produced 

 absorptions which varied between 20 and 28. 



In the teas, cinnamon, musk, and the odorous plants already 

 referred to, dry air had been passed over them for some time 

 before they were examined. Still a small amount of aqueous 

 vapour may have entered with the odours, and thus rendeicd the 

 results to some extent of a mixed character. 



§ 10. Ozone. — In my last memoir I alluded briefly to the action 

 of ozone ; but the experiments then made having been executed 

 with a brass tube, I was very desirous of repeating them with a 

 tube which could not be attacked by this extraordinary substance. 

 Experiments with the glass tube, performed on the 16th, 17th, 



2A2 



