IV. TECHNICAL. 539 



2734. No. 9. Copper Precipitate thrown down by the 

 immersion of thin scrap iron in the cupreous solutions. 



Widnes Metal Company. 



(Contains on an average 75 to 80 per cent, of metallic copper.) 



2735. No. 10. Spent Liquor, or liquid remaining after com- 

 plete precipitation of copper from solution. This liquor is run to 

 waste. Widnes Metal Company. 



2736. Max Liebig's Apparatus for determining, for tech- 

 nical purposes, the quantity of oxygen and carbonic acid con- 

 tained in various gaseous mixtures. 



Joint Stock Company, " Rhenania," Stolberg, near Aix- 

 la- Chapelle. 



A description of this apparatus will be found in Ding. Polyt. Jo urn., 

 Jan. 1873, of which copies may be had. 



2737. Demby's Amylometer (potato-tester) accompanied 

 by a description and case. F. H. Bitchier, Breslau. 



This instrument is quite new (1875). It is remarkable for its simplicity 

 and accuracy, as well as for the rapidity with which the starchy matter in 

 potatoes can be estimated. Earn water may be employed. 



2738. Stammer's Testing Apparatus applicable to all the 

 processes met with in distilleries, accompanied by a descriptive 

 treatise. F. H. Stickler, Breslau. 



This apparatus is quite new. It comprises absolutely true standard hydro- 

 meters for the determination of specific gravities, and replaces (for the most 

 part) the purely empirical methods of testing which have hitherto been in use, 

 by rational chemical methods. 



2738a. Drawing of Root's Patent (special) Blower for 



Hargreaves' process in the manufacture of sulphates. 



Thwaites $ Carbittt, Bradford. 



2738b. Model of Boot's Patent Pressure Blower. 



Thwaites $ Carbutt, Bradford. 



2738e. Artificial Fruit Essences, being solutions of various 

 organic ethers in rect. spirit of wine. Hirst, Brooke, and Hirst. 



They arc nearly identical in flavour and chemical composition with the 

 flavouring principles of the fruits they are intended to imitate : 

 Jargonelle pear. Raspberry. 



Pine apple. Greengage. 



Apple. Peach. 



Strawberry. Cherry. 



