Specifications for Glassware. 258a 



graduations shall be 2 mm. longer than the five-tenths per cent 

 graduations, projecting 2 mm. to the left; the 5 per cent gradua- 

 tions shall extend half way around the neck to the right and pro- 

 ject 4 mm. to the left of the five-tenths per cent graduations. 

 Each 5 per cent graduation shall be numbered, the number being 

 placed on the left of the scale. The error at any point of the 

 scale shall not exceed five-tenths per cent. 



Neck: (Same as standard milk test bottle.) The neck shall 

 be cylindrical for at least 9 mm. below the lowest and above the 

 highest graduation mark. The top of the neck shall be flared to a 

 diameter of not less than 10 mm. 



Bull> : (Same as standard milk test bottle.) The capacity of 

 the bulb up to the junction of the neck shall not be less than 

 45 cc. The shape of the bulb may be either cylindrical or conical, 

 with the smallest diameter at the bottom. If cylindrical the out- 

 side diameter shall be between 34 and 36 mm.; if conical, the 

 outside diameter of the base shall be between 31 and 33 mm. and 

 the maximum diameter between 35 and 37 mm. 



The Charge of the bottle shall be 9 grams. All bottles shall 

 bear on top of the neck above the graduations in plainly legible 

 characters, a mark defining the weight of the charge to be used 

 (9 grams). 



The Total Height of the bottle shall be between 150 and 165 

 mm. (5% and 6% inches). (Same as standard milk test bottles.) 



Each bottle shall bear a permanent identification number. 



B. 5C% 9-gram, so-called 9-inch. 



The same specifications in every detail as specified for the 50% 

 9-gram 6-inch cream test bottle shall apply to the 9-inch bottle, 

 with the exception, however, that the total height of this bottle 

 shall be between 210 and 225 mm. (8*4 and 8% inches). 



III. The Standard Babcock Pipette. Total length of 

 pipette not more than 330 mm. (13^4: inches). Outside diameter 

 of suction tube 6 to 8 mm. Length of suction tube 130 mm. Out- 

 side diameter of delivery tube, 4.5 to 5.D mm. Length of deliv- 

 ery tube, 100 to 120 mm. Distance of graduation mark above bulb, 

 30 to 60 mm. Nozzle straight. Delivery 17.6 cc. of water at 20 

 degrees C. in 5 to 8 seconds. 



In view of the fact that the skimmilk bottle can give only ap- 

 proximate quantitative results, it should be given no consideration 

 as a standard bottle. 



