:>i 



DENSITIES OK UXVCiKN AND HYDROGEN 



Kio. 22a. — Desiccator. 



tliiouirli the axis of the reversal apjiaratus, and 

 eoiiM therefore 1)6 ooiitiiiued without iiiterruptiou 

 except for the i»iirpose of weighing. 



'I'iic volniues suspended from tlie opposite 

 pans of the hahmce were always made ((jual, as 

 in the previous series of determinations, and the 

 weighings were nia<le by reversal in pi-ecisely the 

 same way. 



38. 



-o.\\(,i;N V.\ I IIIIMi MKrilOD. WKKUrr OF GLOHKS WIIKX KXII.M'STKD. 



As already observed, it was thought proper to determine the amount of 

 «)xygen in the gh)be Ity determining the ditferenee of weight between the tilled 

 globe and the globe exhausted immediately afterwards. In this exhaustion and 

 the subse(iuent weighing, leakage through the stopcock of the globe was pi-eventeil 

 by the niani[)ulation described on page 47. Now, since the tare of the globe 

 thus obtained was only for the one experiment immediately preceding, the weight 

 of the joint shown in Fig. 20, and used to prevent leakage, did not need to be 

 known. The joint was therefore made ready for application to the globe when the 

 latter was to be weighed w itli its contents of oxygen, and was, during that weigh- 

 ing, put on the balance with the globe. After the weighing was completed, the 

 joint was put on the globe, a vacuum was produced, the joint was closed by fusion, 

 and tlif globe with the joint was weighed again. The difference of these two 

 weighings (in which the volumes on the opposite pans were made equal as usual) 

 gave the weight of the oxygen contained in the globe. 



Since there was no room for any exercise of judgment in tlie coMildnatioii of 

 observations made in this way, it is sufficient to give simi)ly the number of the 

 globe employed, the pi'essui-e, the weight of oxygen, and the density of oxygen 

 found. The capacities of the glolus have already been given. 



yj. — OXYOKN nV TIIIKD MKniiHi. oliSKKV AllOXS .\M) RKSUI/rs. 



The restdts obtained by the method in which the globes were filled with 

 o.xygen at the temperature of melting ice were as follows. It may be said that 

 three observations were made with the c:lol)e numbered 6. But it wtvs found that 

 an error hail been made in the computatinn <if the voliinic of its counterpoise, so 

 that all the ob.servatioiis made with it were subject to an uncertain and variable 

 correction for the difference of the volume of the globe and its counteriioi.ses. 

 These three results were therefore rejected. 



