BUREAU OF ANIM.Uj INDUSTRY. 269 



preparation, and the remainder are being held for examination after 

 the hipse of difi'orent intervals of time. It is hoped by this study to 

 determine whether or not any undesirable change takes place in 

 canned meats after the lapse of a number of j^ears. 



During the past fiscal year the cooperation of the Biological Survey 

 of the Department was secured in a study of the problem of ridding 

 packing houses of rats, and an expert of that Bureau visited a num- 

 ber of large establishments at National Stock Yards and Chicago, 111. 

 A report of his iuAestigation has been used as a basis for instructions 

 to inspectors as to measures to be adopted to destroy and exclude rats. 



BRANDIXG INK. 



A systematic effort has been made during the year to improve the 

 branding of inspected meats. A study of branding meats has been 

 made at a large number of the meat-inspection stations, and the result 

 has been to increase materially the efficiency of the marking. During 

 the year 4,137 gallons of branding ink prepared by the Biochemic 

 Division were shipped to inspectors in charge of "meat inspection. 

 The total cost of the ink, including materials, labor, and containers 

 for shipment, was $2,373.50. 



DIPS AND DISINFECTANTS. 



_ The work on dips and disinfectants during the past year has con- 

 sisted of (1) routine examination of substances used or offered for use 

 in official dipping, and (2) special or research work. 



The routine work has consisted in the examination of samples sub- 

 mitted l:)y manufacturers, in the examination of samples of permitted 

 dips which have been sent in by field inspectors, and in the examina- 

 tion of samples of disinfectants for the general supply committee for 

 government departments located in Washington. A comparatively 

 small number of samples of new preparations offered for use in official 

 dippings have been submitted by manufacturers during the year. 



Laboratory experiments in the preparation of a concentrated arsen- 

 ical dip for the use of the Bureau employees in the work of tick 

 eradication resulted in securing a dip which possessed the necessary 

 qualities in so far as the solution itself was concerned, and larger 

 quantities were sent to the field for trial. These field experiments 

 are not completed, but the indications are that the preparation will 

 be satisfactory. 



A chemical and bacteriological study of phenolic disinfectants, 

 begun during the previous year, has been continued, but is not yet 

 completed, although decided progress has been made. 



Several cases of injury to sheep following dipping in coal-tar 

 creosote and cresol dips were reported during the year, and as the 

 cause of the injuries was not apparent from the reports received, a 

 special detail of a veterinarian and a chemist was made to investigate 

 the cases of injury and study the question at dipping centers where 

 losses had occurred. The results of this investigation indicate that 

 loss after dipping is usually caused by the combined action of a num- 

 ber of different influences, such as the condition of the sheep, the dip, 

 and the handling of the sheep after dipping. If the sheep are un- 



