153 



in bottles to insure uniformity, but a letter from the Borden Company, who furnished 

 th.- mnplee, !>. -ribing their process, whereby the milk is continuously agitated 

 until it reaches the cans, convinced the writer that all cans from the same batch 

 must be as uniform as it is possible to make them. 



INSTRUCTIONS FOR ANALYSIS OP CONDENSED MILK. 



Preparation of sample. 



Mix thoroughly by transferring the contents of a can to some dish sufficiently large 

 to thoroughly -tir and nuik.- the whole homogeneous. Weigh 40 grams into a 100 cc 

 flask and make up to the mark with water. 



Total solids. 



M,tl,n<l A. Dilute a measured portion of the above 40 per cent solution with an 

 equal amount of water. Use 5 cc of the diluted mixture and proceed as in the case 

 of mi Ik anal\-i~ according to the method given in Bulletin 107, page 117, Method I 

 drying either on aand or asbestos fiber. 



Mittinil /;. I ~e l., M, h'- method which is as follows: Dilute a portion of the 40 per 

 cent solution with an |iuil amount of water and take enough of this solution to 

 repre-ent I -nun of the condensed milk. Put in a tared platinum dish which will 

 hold at lea.-t _'." cc and -till further dilute with water until the dish is nearly full, 

 rin-iiiu' the pipette into th- dish, then allow the dish to remain in contact with live 

 steam fm at |ea-i two h<-ur- after the last traces of the water have apparently been 

 evaporated, then transfer to the drying "\en for a few minutes, cool in the desiccator 

 and \\ejijh. 



Ash. 



Ignite the residue from total solids, cool and weigh in the usual manner. 



1'rott in . 



I ' termine nitrogen by Kjaldahl or Gunning method in 5 cc of the 40 per cent 



solution and multiplv l.\ 



Lactose. 



of the Hi per cent solution in a 250 cc flask to about 200 cc, add 6 cc 

 "t Fehlinj pper -ulphaie -olution. and make up to the mark, filter through a dry 



Idler and d- t- mime lactose as follou-: 



h of the copper sulphate and alkaline tartrate solution, add 50 cc 

 water and brim: to boiling, then add 2~> cc of the filtered milk solution and boil two 

 minute- by longer boiling the sucrose appears to throw down some copper), remove 

 from the lamp and allow to settle one or two minutes then filter on a gooch crucible 

 in the n-ual manner, wemhinu' the cuprous oxid after drying at 100 degrees. Give 

 M- of < nproii- oxid found as well as percentages of lactose so methods of calcula- 

 tion can be compared. Also, if possible, determine lactose by polariscope in this 

 solution. 



Sttcrose. 



Place 25 cc of the above solution, used to determine lactose, in a 100 cc flask. Add 

 of water and 'am of citric acid and heat on the steam bath for thirty 



minute-, nearly neiitrali/.e with -odium hydrosid and determine total sugars in 25 cc 

 with I'ehlin/- solution in the usual manner, giving the weight of cuprous oxid as 

 well a.- the per. entases of .-ucrose. Also determine sucrose by difference, subtracting 

 the lactose, protein, fat and ash from total solids. 



Fat. 



/ A- Determine by double extraction method. (See Bureau of Chemistry, 

 Circular 32. p - 



M.tt.n.t H. llv the liabcoek centrifugal method using the modification given in 

 Bulletin 107. pu-ie I 



Method ( . The ( Gottlieb method, the directions for which are as follows: 

 Ten cubic centimeters of milk are measured into a glass cylinder three-fourths inch 

 in diameter and about 14 inches long (see Landw. Vers. Sta., *>:: 100 cc burette 

 or ft eudiometer tube will do); Ice of concentrated ammonia is added and mixed well 

 with themilk The following chemicals are next added, in the order given: 10 cc of 

 !L' per cent alcohol, 25 cc of washed ether, and 25 cc petroleum ether (boiling point 



