261 



Thus the following slip : — 



D.j 0250 Halogens | 



Shenstone, W. A. <()bservations> | ... | on the 



/[preparation and]! properties o!' <sorae highly purified 



substances^ | . . . [dry halogens] I. London. J Chom. 

 Soc, 71, 1897, (471-488). <[0250]>, 



would be understood to signify an author's slip : — 



D. 



Shenstone, W. A. Observations on the properties of some 

 highly purified substances. London. J. Chem. Soc, 71, 1897, 

 (471-488). [0250], 



and a subject-catalogue slip : — 



D. 0250. Halogens. 



Shenstone. W. A. . . . On the [preparation and] pro- 

 perties of . . . [dry halogens]. London. J. Chem. Soc, 

 71, 1897. (471-48«). 



General Instructions as to Preparation of Slips. 



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 that it is desired to write upon it, a second slip must be used, 

 and tied to the first through the hole. 



74. The Regional Bureaux are requested to retain duplicates 

 of the slips sent in by them, until the volume containing the 

 entries on these slips is published. The object of this regulation 

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75. Whenever any Regional Bureau sends slips to the Central 

 Bureau, the Regional Bureau should send an independent post- 

 card to the Central Bureau, stating — 



a. The number of Authors' slips sent. 



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The Central Bureau will acknowledge the receipt of slips. 



