volllmc of tlieir work in 1927, which denlt wit,li the suhjects A to By-products, togct,licr witli ii complctc list, of pntcntccs for thc fire volumes. IWli tlic issue of the t,liird, fourth, nnd fift,li volunies wit,liiii n few months of encli other, tlic present task is co~iiplctcd. I-Inring finislied this index, which cowrs thr subject matter, specifications, nnd cliiims, of United States patents nnd pitent re-issues griinted dnring the decenninl period 1015-1024, the iiuthors propose to work bsckwnrds to cover tlic complete peries of Aniericnn patents to li90 ! JIorcover, they hnvc dccidcd to issue 1)ieniiiiiI volumes to keep t,he index UP to diltc.
22,882 pntcnts Iinvc becii intlcseil for this work, ii list of which is included u t the end of the List volume. There nre 531,260 sepiirntc references for the letters A to Z which lire condensed into 5321 pages. Some idea of tlie work involved inny be realized when t,hc 15,400 references to iron, tlic 17,000 to cntalyst, or the 11,000 to cellulosc arc seen.
So criticism cnn be levelled iit this work ; it is ii t.rentisc that is one of tlic classics of cheniiciil literntiire, it work tlint the nut,liors can be jnstly proud of, nnd one that will rapidly bccornc of intcruationul repute. I?. 11. c.