310 



THE GENESEE FARMER. 



and which combining with liydropten (also liber- 

 ated bv dectini|)iisir,it)n) forms ammonia, which am- 

 monia becomes absorbed by the soil or dissolved by 

 rains, and tlius becomes useful as a food to plants. 

 The other jiart is carbon, also iisefnl to vegetable 

 life. In some bones it will be as Ppgh says, four 

 per cent., (which is jvrobably the minimnm) and in 

 others, as Stockiiarot says, is 33 per cent, (wiiich 

 is probably tiie n>axiinuni.) But wiiether four per 

 cent, or thirty-tliree percent., they are all destroyed, 

 or rather driven off, by burning, and little except 

 the mineral part of bones is left. The farmer 

 must, therefore, remember that by burning bones 

 l>e loses all thcanhnal matter they contain, whether 

 it be more or whether it be less. He shottld also 

 remember that the fresher and more recently the 

 bones are from the animal, when crushed, the 

 richer and more [>owerfnl the dressing; and also the 

 fatter and more healtliy the animal from which the 

 bones are taken, the richer and more powerful they 

 ■will be as a fertilizer. Tiius, health and fatness 

 pervade the animal to its very bones and add to its 

 value and nsefuiuess in its very ultimates. — Maine 

 Farmer. 



Remarks. — There is no real discrepancy between 

 the above statements of Dr. Pugh and Prof. Stook- 



HABDT. 



The correspondent of the Farmer mistakes the 

 meaning of Prof, Stockhakdt's stateraect in re- 

 gard to the amount of nitrogen in bones. The sen- 

 tence, as quoted, is rather ambiguous, but the mean- 

 ing is this: Bones contain 33 per cent, of gelatine. 

 This gelatine contains a great abundance of nitro- 

 gen (17 per cent.). When the bones are burnt, the 

 gelatine is destroyed and the nitrogen is lost. 



In burning a quantity of bones how niuch nitro- 

 gen is lost? Dr. Evan Pugh says four per cent. ; 

 Stockhardt says we lose 38 per cent, of gelatine. 

 Kow, as gelatine contains 17 per cent of nitrogen, 

 we should lose between 5 and 6 per cent, of nitro- 

 gen. In his Chemical Field Lectures Stookhardt 

 states that bones contain 5 per cent, of nitrogen. 

 The difference is not very great. Dr. Puon is 

 doubtless nearest the truth, so far as ordinary 

 commercial bones are concerned. But the corre- 

 spondent of the Maine Farmer evidently supposes 

 SxocKnAHDT-to mean that bones contain 33 per 

 cent, of nitrogen. This is a mistake. He means 

 that bones contain 33 per cent, of gelatine, a sub- 

 stance "that contains a great abundance of nitro- 

 gen." 



Some years ago a Boston chemist analyzed a 

 sample of the so-called Chilian guano, and reported 

 that it contained " organic matter yielding ammo- 

 nia, 20 per cent." Farmers who saw this analysis 

 very naturally supposed that the guano contained 

 20 per cent, of ammonia. But a sample of it an- 

 alyzed by the writer of tliis was found to contain 

 • only 1 per cent, of ammonia. Now, was there any 



discrepancy between the two analyses ? Not at all. 

 It is a different way of stating the results of the ex- 

 amination. The guano did contain 20 per cent, 

 of organic matter, and this organic matter would, 

 by deeompositioB, " yield ammonia." And this 

 was all that the Boston chemist stated, though the 

 phraseology might have been intended to deceive. 



We make these remarks in the hope of enabling 

 our readers to understand these matters more 

 clearly. It is important to understand the real 

 significance of a chemical analysis. Four per cent, 

 of nitrogen and 33 per cent, of gelatine is (nearly) 

 one and the same thing. 



GRUBS ON CATTLE. 



Friend Harris : Tn your May number of the 

 Oenesee Farmer J. E. Pierson asks, "What is the 

 cause and what is tlie cure of grubs in the backs of 

 cattle?" and says his young cattle are very much 

 infected and very poor in consequence. 



Warbles, or gii>bs, in the backs of cattle are the 

 larvse of the gad-tiy (the OrstrusbovL* of the ento- 

 mologists). The fly, in July and August, alights 

 on the back of the cow, pnnctnres the skin and de- 

 posits its eggs. In a short time the grub is hatched, 

 and eventually worms its way through the hide, 

 where it remains, feeding and growing through 

 the winter. In the s])ring it has attained its growth, 

 and escapes throniili a round hole in the hide. It 

 then burrows in the earth, changes to a perfect or 

 winged insect, and then emerges, takes wing and 

 pursues the com-se of its parent — that is, attacks 

 the cattle for the purpose of continuing its species, 

 in accordance with those natural laws designed for 

 the perpetuity and annual rei)ro(]uction of the ge- 

 nus, gad-fly. Sometimes as many as one hundred 

 of these grubs are found l)eneat]i the skin of a sin- 

 gle animal — each boring its own passage through 

 the skin. During the time the grubs are under the 

 hide, the animal, no doubt, suffers much pain, and 

 sometimes become "very poor in consequence." 



I know of no way in which the fly can be kept 

 from depositing its eggs in the backs of our cattle, 

 I do not suppose that the])uiicture made by the fly, 

 in which to deposit eggs, causes the animal so 

 much pain as the piick of a ])in would; yet, when' 

 a single gad-fly attacks'a herd of cattle, it seems to 

 cause a most alarming, instinctive fright. "The 

 cattle will stick up their tails and run as though 

 possessed," enacring a real Bull Run stampede. 



In the spring tlie grub can sometimes be pressed 

 out and destroyed. All such will, of course, de- 

 posit no eggs in the backs of old or young cattle. 

 "It has been said that strong brine wW destroy 

 the grubs in any stage," but I very much doubt the 

 correctness of the saying. It is truly wonderful 

 how many ways have been brought into requisition 

 to keep up and continue the various species and 

 tribes of insects, and what transformations they 

 undergo, from the time the egg is deposited to the 

 final and full api)earance of the perfect insect. 

 Many of these " changes are very similar to what 

 it would be for a serpent to become a clam or oys- 

 ter, and this clam to subsequently change into a 

 bird." To those of studious and inquisitive minds, 



