Vol. XV. No. 370. 



THE AGRICULTURAL NEWS. 



22.3 



At Estate E, we were informed tliat the unfavourable 

 con<lition of the cacao was due to extensive removal of fairly 

 dense ghade. Root disease was remarkably absent, although 

 the conditions were such as might have been expected to have 

 led to serious outbreaks. This we regard as confirmative 

 of our ideas as to the relatively dry oouditions brought about 

 by the nature of the St. Vincent soil, it being well established 

 that root disease is directly dependent on the persistence of 

 damp conditions. Even at Estate A, the type of root disea.se 

 mostly found is that which occurs in Grenada in the relatively 

 dry localities. 



The adoption of a regular .system of manurial treatment 

 such as has been outlined for use at Estat;e A would be bene- 

 ficial at Estate E; the restoration of proper conditions as to 

 shade and wind-belts would seem to be a necessity. 



It was suggested to the manager that trials should be 

 made of contour trenches in a small way on one of the steeper 

 slope.s, for the con.servation of surface water. At this place 

 there is a substratum in the soil which probably causes 

 a large amount of the surface water t'l run ofi'. The suggest- 

 ■ed trenches should allow nmch of this water to penetrate 

 into the soil. 



At the E.xperiment Station, the small plot of cacao is in 

 good health, and shows in rather a striking manner the validity 

 of our contention with regard to thrips, since thrips are 

 always present on a fruit tree adjacent to the plot, and are not 

 Able to penetrate within its border. 



At the Botanic Gardens the trees in certain portions of 

 the cacao plots are in an un.satisfactory condition for which 

 we are not able adequately to account. In view, however, of 

 of the accumulated evidence as stated above, we are not 

 inclined to attribute this to the effects of the thrips attack 

 without the action of some predi.sposing cause. 



THE COMPOSITION OF MILK IN THE 



TROPICS. 



In connexion with the article that appeared in this 

 Journal a few months ago (.\pril 22, 19 16) on the composition 

 of Dominica milk, it is of interest to notice two important 

 papers on the subject of milk analysis, which have been issued 

 by the Mauritius Department of Agriculture, and by the 

 Agricultural Researi-h Institute, Fusa, India, respectively; 

 namely, the Coinpo.sition of Milks of Mauritius, by G. G. 

 Auchinleck, B.Sc.,and the Detection of Added Water to Milk 

 in India, by .J. W. Leather, V.D , F.I.C. The first publi- 

 cation .shows that in Uctose, albuminoids and ash, Mauritian 

 milks are lower than the average English and French milks, 

 while in fats tLey are higher than the French and lower than 

 the English average. The legal minimum percentage of fats 

 in fresh milk offered for public sale is, in England, 3 0: for 

 Mauritius, it is at present fixed at 2 o per cent. The average 

 percentage of fats in morning milks is lower than that of 

 evening milks. This difference in composition is presumably 

 due to the fact that the periods between the niilkings are 

 unequal. 



In regard to the use of empirical formula? for calculating 

 one of the constituents when the two others are known, it is 

 •stated that Richmond's formula — 



Total solids =12 fat -i- -2.5 gravity -i- ■ 1 4 



gives for Mauritian milks results too low in the case of total 

 solids and too high in the c ise of fats. It is of interest to 

 observe that the percentage of total solids and fat.s are 



lower in Mauritius milk than in that produced in Dominica 

 in the West Indies. 



The second publication, dealing with the detection of 

 added water in milk in India tioncerns principally a method 

 of determining this by means of freezing. It is stated that 

 attention has lately been directed to both the refractive 

 index of the milk serum, and to the freezing point of the 

 milk for purposes ef detecting added water. The former has 

 not been used by the writer of the Bulletin under notice, 

 but judging by published data, this method will hardly 

 detect 10 per cent, of added water The latter method is 

 stated to be more dependable, however, and has been used 

 rather extensively. The formula is — 



W= -174(-0'5i2-t) 



where t is the freezing point and W the weight of water added. 

 As regards the accuracy of this method, it is stated that 

 it has to be realized that any dairyman who waters his milk 

 win not add so little as b per cent., it is unlikely that he 

 would add less than .some 10 to 20 per cent.; which assump- 

 tion makes it quite certain that adulteration by water can be 

 detected with certainty except in the improbable case of less 

 than 5 per cent, being added when the freezing method is not 

 reliable. 



It is stated that this method is obviously very much 

 more certain than the deduction from the percentage of 

 solids-not-fat. With reference to the method of ascertain- 

 ing the freezing point, little explanation is required in 

 addition to the details commonly employed in cryoscopic 

 determinations. 



The writer, Mr. Leather, found it best to employ a bath 

 of ice and salt solid, and to place the milk in a tube which, is 

 itself in an outer empty tube, the latter being in contact with 

 the bath. The temperature of the milk usually suiiercoals 

 from ]|' to 2°; as soon as ice commences to form, the tem- 

 perature rapidly rises to the true freezing point. Half-a- 

 minute is allowed to elap.^e between each reading of the 

 thermometer, and at the freezing point the variation of tem- 

 perature is not more than 0'002 C. The thermometer should 

 be steady within this limit for at least two minutes. 



A note in the International Rei'iewof the Sci'.nce and 

 Practice of Agrii-ulture states that plants watered with salt 

 solution show varying i.legrees of difference from individuals 

 of the same species watered with ordinary water. It is stated 

 that the characters induced are transmitted ; these are small 

 .size, smaller proportions of large .seeds, reduced weight of the 

 seed. These characters, however, can be found in plants grow- 

 ing under unfavourable conditions of any kind; consequently, 

 in order to be able to settle the question definitely, more ex- 

 periments are necessary. 



The Went India Committee Circular refers, in its issue 

 for .June 1, to the development of the Indian sugar industry 

 as urged by Tropical Life. This latter journal points out 

 that if the Indian Empire produced the 800,000 tons of 

 white sugar that, she at pre.sent imports, plus another .^Oi.i.OOO 

 tons to send to the. f'nited Kinsidom, .^he would be 

 £26,000,000 a year richer at £20 a ton, and halt as much, 

 again if calculated on a basis of £.30 a ton; and to do thisshu 

 has only to produce 2 tons of white sugar per acre as compli- 

 ed with over 4- tons per acre, the average return in .Java. 



