American chemical journal . ,automatically. On opening the stopcock of the charged gasom-eter, mercury will pass over until it is on a level in both bottles,and the remaining half can be expelled by applying pressure tothe bent tube of the second bottle. A well-constructed apparatuswill keep a gas for weeks without an appreciable change. I wish finally to call attention to a slight modification of Hof-manns well-known V tube, which permits the collection of boththe products of decomposition, andcan, therefore, be used for quantita-tive analysis. On the upper side ofthe bend of the tube a glass
American chemical journal . ,automatically. On opening the stopcock of the charged gasom-eter, mercury will pass over until it is on a level in both bottles,and the remaining half can be expelled by applying pressure tothe bent tube of the second bottle. A well-constructed apparatuswill keep a gas for weeks without an appreciable change. I wish finally to call attention to a slight modification of Hof-manns well-known V tube, which permits the collection of boththe products of decomposition, andcan, therefore, be used for quantita-tive analysis. On the upper side ofthe bend of the tube a glass tube isconnected, which is an inch higherthan the limbs of the V tube (Fig. 4).The limbs are graduated in five or sixequal parts ; those on the open limbbeginning, not at the open end, butabout one half an inch from it. Foruse, the apparatus is filled with liquid,and the cork, through which a glass A more advantageous form is to have the delivery tube connected to the neck of the gasom-eter, directly under the rubber Acetylchloride and Acetic Anhydride on Starch. 359 tube with platinum electrode passes, is pressed into the open limbuntil it reaches the first graduation. The displaced liquid flowsout through the middle limb, which is conveniently connected witha rubber tube. Ungraduated Ures eudiometers, provided with ashort horizontal tube on the lower side of the bend, or on theupper side and bent downwards, make a cheap and efficient sub-stitute for Hofmanns lecture-eudiometer, especially for studentsuse in the laboratory. XI.—OBSERVATIONS ON THE ACTION OF ACETYLCHLORIDEAND ACETIC ANHYDRIDE ON CORN AND WHEAT STARCH. The following preliminary experiments on the action of aceticanhydride and acetylchloride on corn and wheat starch were madewith a view of ascertaining whether the typical physical differencesof these varieties of starch are noticeable in their acetyl to Schiitzenberger, starch heated with acetic anhydrideat 140° yields an amorphou
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherbalti, bookyear1879
