in; 



<>f the harmless species on the surface of a filter bed largely increases 

 the efficiency of the filter : and some authorities go so far as to saj 

 that no filter-bed can be perfect without them, but in this instance also 

 it is known that when this layer becomes too full of miscrocopic animal 

 life, it must be removed or the supply of water will not be of 

 standard quality. 



The Algae that arc known to take up calcareous matter from 

 water are fairly prominent in Trinidad, and specimens of these can be 

 readily seen. The Diatomaca.' which take up silica, when boiled in 

 Nitric acid and deprived of organic matter exhibit the most beautiful 

 markings when seen under a compound microscope, and the writer 

 has found numerous rare specimens in the salt and fresh waters oi 

 Trinidad. 



The species of Alga? which accumulate calcareous matter, will 

 render the water softer, aud better fit for domestic use, by ridding 

 it of excess of lime. 



It is to be seen therefore, that while objectionable Ahjee or green 

 slime clearly exists ; there are at the same time numerous harmless 

 forms, and that some of the latter are actually beneficial, and that it 

 is necessarv to discriminate between them and not to condemn all on 

 account of the few objectionable members. 



Such discrimination is possible, and can easily be made by those 

 conversant with the Hygienic principles which should govern and 

 control the water supplies of large towns. 



Our examination appears to lead to the conclusion, that the pre- 

 sence of Algse or "green slime " in water supplies should not be too 

 hastily condemned, and that those who do so should be asked to 

 explain which species, if any, is harmful. In general, public discus- 

 sions on such matters are delightfully vague ; it being a much easier 

 matter to condemn on suspicion, than to define what is, or is not, the 

 actual cause of contamination in a water supply, and in many cases the 

 cleverest analysts report in terms of suspicion only, without a 

 definition of the actual cause. 



658.-THE BUDDING OF ORANGES. 



[n several cases application have been made to the Department 

 for instruction in the budding of Oranges. When the Instructor has 

 appeared on the spot it has been found that no material was available 



for the purpose, and the demonstration has had to be postponed. 



For the information of those desirous of producing budded 

 oranges or other citrus fruits, it is necessary that the following 

 preparations should be made. 



1st. Procure Seville or sour orange seeds, taken from ripe fruit : 

 ami sow in rows 18 inches apart in be ! s in the open ground, thinning 

 the plants, when the seeds have germinated, so as to have them stand 

 9-12 inches apart in the row. Allow the plants to grow until the 

 stems are about the thickness of a lead pencil, and from IS inches, 

 to two feet in height: when the) will be lit for budding. 



