A NEW APPARATUS FOR DRYING SUBSTANCES IN 



HYDROGEN AND FOR THE EXTRACTION 



OF THE FAT. 



A T the last meeting of the Association of Official Agricultural 

 -^^ Chemists, it was voted that in the analysis of cattle foods the 

 substance should be dried, for the determination of moisture and 

 ether-extract, in a current of dried hydrogen, at the temperature 

 of boiling water, and that the glass containing the substance should 

 not come in contact with the water. It seemed to me at first well 

 nigh impossible to fulfill this last condition ; and it may be that 

 this precaution is unnecessary ; but if it can in any way easily be 

 observed, it is certainly well enough to do so. 



The, form of drying bath and tube shown in the adjoining figures 

 seems to meet the requirement fully, while at the same time it 

 makes it also possible to carry the hydrogen directly through the 

 substance instead of over it as usuall}' done, thus securing more 

 rapid drying, to weigh the substance before and after drying in a 

 perfectly tight tube, and to use one and the same portion of the 

 substance for the three determinations, moisture, ether-extract and 

 fibre, without inconvenience, and without any danger of loss of 

 substance in the single transfer from one vessel to another that is 

 necessaiy. 



It is also easy to heat the hydrogen to the temperature of the 

 boiling water before conducting it through the substance, a modi- 

 fication that seemed desirable to some members of the Association. 

 My own bath has a coil of about four feet of eighth-inch tin pipe 

 in the bottom ; one free end of this passes up inside one end of the 

 bath, and out, to connect with the hydrogen-drying apparatus ; 

 the other end of the pipe passes up at the other end of the bath to 

 near the top, where it is connected with a piece of quarter-inch 

 pipe, running back as far as the other end of the bath, and from 

 which arms of the smaller pipe pass out along the side, and then 

 down to connect by rubber tube with the drying tubes. This ad- 

 dition was put in for the purpose of making a thorough test of the 

 efficiency of previously heating the hydrogen, which test we have 



