LABORATORY SUPPLIES AND CHEMICALS 



81 



Replacements : 



Thermometer 65 90 F. with certificate $12.00 



Thermometer 65 105 F. with certificate 13.00 



New Thermometer Reading Lens 3.00 



Ignition wire, electric, per card 75 



Gaskets for bomb, per dozen 50 



Chemical ^per J4 Ib. can (special sodium peroxide) 1.10 



Chemical per y 2 Ib. can (special sodium peroxide) 1.95 



Chemical per 1 Ib. can (special sodium peroxide) .' 3.00 



Accelerator per bottle, 2 oz. capacity 1.00 



Special chemical, per bottle 1.00 



2177 PARR'S NEW PEROXIDE CALORIMETER BOMB. 



A new and greatly improved form of bomb for the Parr 

 Standard Calorimeter has been devised which has marked 

 advantages over the old pattern. A summarized statement 

 of advantages for more convenient reference is given below: 



1. A removable fusion cup, or crucible, is provided with 

 an extra cup for duplicating determinations. These cups are 

 made of a special alloy which is immune to the action of 

 the fused alkali. The materials making up the charge can be 

 weighed out and added directly to the cups, which may then 

 be transferred to the holders for use as desired. 



2. The electric terminals are short and sturdy, and do 

 not become bent* or broken by use. 



3. Provision is made by means of an air space about the 

 fusion cup whereby the cup is permitted to come to a red 

 heat, after which the surrounding water is brought into con- 

 tact with the cup for quick extraction of the heat. This high 

 temperature throughout the mass avoids the cooling eect 

 of metallic walls which are in contact with water, thus secur- 

 ing a complete combustion with all types of coals. 



4. By use of the fusion cups a removable bottom is 

 avoided and the process of cleaning out the fusion is very 

 much expedited. The cups are short enough to readily go 

 into a small No. 3 or No. 4 beaker lying flatwise, in which 

 way the fusion is readily dissolved out without loss. 



5. The electric contacts are simplified and made much 

 more convenient. 



6. A simple additional accessory makes it possible to 

 use the fusion cups for sulphur determinations alone. This is 

 without doubt the ideal method for making a determination 

 of sulphur in all organic compounds and especially to be 

 recommended for use in determining the sulphur in coal. 

 See description following under No. 2179. 



Price $35.00 



2177 



2179 PARR'S NEW SULPHUR BOMB. 



sac 



For sulphur determinations which are to be made inde- 

 pendently of the calorimetric process, a special apparatus, 

 as shown in Fig. 2D, has been devised. An adaptation 

 has been made of the same fusion cup as that used in the 

 calorimeter bomb (Fig. 2A). By reference to Fig. 2D, it 

 will be seen that the fusion cup (2AC) has a cover (7AC) 

 with a gasket (27AC), and a screw cap (5AC), by means 

 of which the container is tightly sealed. The lower half 

 of the fusion cup, however, is exposed, and by applying 

 heat to the bottom of the cup the charge is readily ignited. 

 After a moment, it is held under the tap for cooling, after 

 which the cup is removed and the fusion dissolved otft. 

 In this way the solution containing all of the sulphur as 

 sulphate may be made ready for precipitation in less than 

 five minutes and with no possible accession of sulphur from gas flames or other sources 

 of contamination. 



Results obtained by this method are believed to be the most reliable of any, and 

 the time element is decidedly to its advantage. 



, For organic halogens, to replace the ordinary Carius method in the determination 

 of chlorine, bromide and iodine, the use of this bomb will be found exceedingly con- 

 venient and expeditious. 



$23.00 



