166 PROCEEDINGS OF THIRTY-SIXTH FRUIT-GROWERS ' CONVENTION. 



Until the permanent methods of control come generally into use the 

 utmost care should be exercised to keep this most dangerous of disease 

 carriers out of the house. Thus properly screening both windows and 

 doors is important. Grocery stores, fruit stands, candy shops and 

 butcher shops, bakeries and restaurants, which do not protect their 

 wares from the flies, should be compelled to do so by health author- 

 ities and patrons should insist upon this precaution. A little public 

 sentiment in this direction will work wonders. 



The use of the ordinary fly poisons is objectionable, since poisoned 

 flies are liable to fall into prepared foods and cause mischief to the con- 

 sumer. Furthermore, not a summer passes without its toll of innocent 

 children whose lives have been lost, generally in extreme agony, by 

 drinking some deadly fly poison. The writer has found (as already 

 suggested by others) that formaldehyde, properly used, forms a very 

 good substitute for arsenical or cobalt poisons. This liquid material is 

 rather inexpensive when used as indicated and has the added advantage 

 that it is not poisonous to man, and may, therefore, be used with 

 impunity around food; it is also one of the most powerful germicides 

 known and is not injurious to delicate fabrics. Formaldehyde, as pur- 

 chased at the drug store, is in about a 40 per cent solution and should be 

 diluted with water down to 5 per cent to 8 per cent ; in other words, add 

 five to six times as much water. This dilution must now be sweetened 

 well with sugar or other sweet. A good plan is to partly fill a shallow 

 individual butter dish with the diluted formaldehyde and add about 

 one fourth teaspoonful of sugar, then place the dish on the table or in 

 the show window. The flies drink this material and die in great num- 

 bers not far from the insecticide. It is not an eas} r matter to control the 

 fly in a dining-room where there is plenty of liquid material for food 

 and drink, such as water, milk, sweets, etc., but where this can be 

 removed in the evening and the dishes with formaldehyde substituted 

 so that the flies will drink this the first thing in the morning the end will 

 be accomplished much more readily. One is here taking advantage of 

 the fact that the flies seek something to drink as soon as they "awaken" 

 from their sleep in the morning. 



MOSQUITOES. 



"We must now briefly turn our attention to the mosquitoes. Among 

 the several species of these insects existing in the State of California 

 there are also the Anopheles or malarial fever mosquitoes. No fact in 

 medical science is perhaps more certainly established than that malarial 

 fever is transmitted by mosquitoes of the genus Anopheles. However 

 much a man might expose himself to the miasma of swamps and the 

 steaming tropics he could never contract malarial fever except through 

 the bite of an infected mosquito. Malaria is caused by an unicellular 

 animal parasite which lives a certain part of its life in the red blood 

 corpuscles of man. The destruction of these corpuscles when the para- 

 sites are numerous induce the paroxysm of chills and fever, which occurs 

 at regular intervals due to the regular developmental cycle of the para- 

 site. The direct loss of life due to this disease may not seem to be great, 

 but it is one of those affections which produces great inefficiency in per- 

 forming one's ordinary duties. Herrick has well stated the matter thus : 

 "The loss of energy and enthusiasm, the loss of interest in one's own 



