I 

 ( 



24 R. H. A. PLIMMER. 



the course of the large number of determinations which have been made. 

 The re.-ults by the reduction method are quite sufficient to show how far 

 the hydrolysis of the lactose had proceeded. It may be stated that 

 unless the reduction showed 15 20 per cent, inversion, no osazone 

 insoluble in boiling water could be isolated. A few examples will serve 

 to show how this procedure was carried out : 



(1) 120 c.c. toluol water extract of mucous membrane of fowl fed for 14 weeks on milk 

 and lactose mixed with the ordinary food. 



J 100 c.c. 5 % lactose solution, 50 c.c. extract, 2 c.c. toluol 1 Incubated at 38 C. 



1 100 c.c. 5 / lactose solution, 50 c.c. boiled extract, 2 c.c. toluol) for 3 days. 



Then, to each was added 10 c.c. mercuric nitrate solution. Filtered. 130 c.c. nitrate 

 neutralised with 5-5 c.c. 10% NaOH and filtered. 120 c.c. filtrate treated with H 2 S. 

 Exoess of H 2 S removed with CuS0 4 . Made up to 250 c.c. and filtered. 20 c.c. filtrate used 

 for reductions. Rotations of the experiment and the control were + 1 46' and + 1 45' 

 respectively. The osazones, prepared after exactly neutralising and filtering from copper 

 hydroxide, were completely soluble in boiling water and melted at 211 C C. and 212 C. 

 respectively. 



(2) 60 c.c. toluol water extract of mucous membrane of large ? rat, not fed on milk. 



I 50 c.c. 5 % lactose sol., 25 c.c. extract,. 2 c.c. toluol I Incubated at 30 38 C. 



50 c.c. 5 / lactose sol., 25 c.c. boiled extract, 2 c.c. toluol J for 3 days. 



Then, to each was added 5 c.c. mercuric nitrate solution. Filtered. 65 c.c. filtrate 

 neutralised with 3-0 c.c. 10 / NaOH and filtered. 60 c.c. filtrate treated with H 2 S. 

 Excess of H 2 S removed with CuS0 4 . Made up to 250 c.c. and filtered. 20 c.c. filtrate for 

 reductions. 



(3) 60 c.c. toluol water extract of mucous membrane of intestines of two newly-born 

 guinea-pigs. 



J 50 c.c. 5 / lactose sol., 25 c.c. extract, 2 c.c. toluol | Incubated at 36 C. 



I 50 c.c. 5 / lactose sol., 25 c.c. boiled extract, 2 c.c. toluol f for 3 days. 



Then, to each was added 5 c.c. mercuric nitrate solution. Filtered. 70 c.c. filtrate 

 neutralised with 3-5 c.c. 10 % NaOH and filtered. 65 c.c. filtrate treated with H 2 S. 

 Excess of H 2 S removed with CuS0 4 . Made up to 250 c.c. and filtered. 20 c.c. filtrate 

 for reductions. 



With the exception of the larger animals, all were kept in the 

 laboratory so that their actual diet for the various periods was known. 

 In the case of the animals fed on milk and lactose, the fowls received it 

 made up into a paste with their corn, wliich was previously ground ; they 

 ate the food quite well and put on a great deal of fat. The rabbits 

 received it mixed up with bran or oats, the rats and guinea-pigs 

 were fed with bread soaked in milk to which a little lactose was added. 

 Neither the rabbits nor the guinea-pigs cared for this food, but they ate 

 it quite well in the morning before receiving their other food, which 

 consisted of oats and green leaves. 



The following table gives the reduction values obtained with the 

 quantity of glucose corresponding to the average reduction values in 



