102 



The Turnip Mud-Beetle. [may, 



manufacture seems to be the possession of a cheap means of 

 producing electricity, as calcium carbide, the substance with 

 which the nitrogen is combined, is made by heating chalk and 

 some form of carbon in an electric furnace. Experiments to 

 test the manurial properties of this substance were carried out 

 in 1901-3 by Professors Gerlach and Wagner at the Experiment 

 Stations at Darmstadt, Posen, and elsewhere, and Dr. Gerlach 

 put the comparative effect of lime nitrogen at 74 per cent, of that 

 of nitrates. On some land and under certain conditions it was 

 found to be injurious, for instance when applied as a top dressing 

 to quite young plants, and again on land inclined to sourness. 

 Dr. Frank, of the Cyanid Gesellschaft, gives the following direc- 

 tions in regard to the use of this material: — (1) the amount 

 applied should be from 1 to 2 J cwt. per acre, according to the 

 condition of the soil ; (2) it should be mixed with about twice 

 the quantity of dry earth ; and (3) it should be broadcasted a 

 week or a fortnight before seeding, and the soil immediately 

 lightly ploughed so as to bury the manure to a depth of 

 3-5 inches. 



During the past year a number of experiments have been car- 

 ried out with this material, and the results show that lime 

 nitrogen is likely to prove a satisfactory nitrogenous manure. 



The Turnip Mud-Beetle {Helophorus rugosus) belongs to a 

 family of beetles the life histories and food habits of many 

 of which are imperfectly known. The 

 The Turnip best known members of the family are 

 Mud-Beetle. aquatic, both as adults and as grubs, and 

 the grubs may be vegetable feeders or 

 they may be carnivorous. The species of the genus Helophorus 

 are non-swimmers, although they can be found on water, near 

 water, and in mud. They are capable of flight, and species have 

 been found away from water on herbage. 



As to the distribution of Helophorus rugosus. Fowler 

 describes it as " rather local, but widely distributed through 

 England and Wales inland and near the coast, not so common 

 in the North ; Scotland, scarce : Lowlands, Tweed, Forth, 



