478 EXPERIMENT STATION RECORD. 



organisms and possibly against plant poisons, such as poison ivy. The value 

 of the method for protecting a community against typhoid Infection is pointed 

 out. 



Studies on changes in the degree of oxidation of arsenic in arsenical dip- 

 ping baths, R. M. Chapin (U. S. Dept. Agr. Bui. 259 {1915), pp. 12, figs. 2).— 

 This bulletin reports upon field and laboratory experiments which have been 

 briefly summarized as follows : 



"All used arsenical dipping baths may be expected to contain (a) oxidizing 

 organisms which work slowly, but steadily and persistently, and (b) reducing 

 organisms which work very rapidly at times, but spasmodically. The reducing 

 organisms exert an appreciable effect only in vats which are used at frequent 

 intervals for dipping large numbers of cattle. The ordinary vat, used once a 

 fortnight, is likely to show only a slow, steadily progressing oxidation of the 

 arsenic, and periodical analyses or tests must be made if proper dipping 

 strength is to be maintained. 



"Formaldehyde solution (37 per cent), used in the proportion of 1 gal. to 

 every 1,500 gal. (8.5 fluid ounces to 100 gal.) of liquid introduced into the vat, 

 appears a safe and effective means for reducing oxidation to a low figure. But 

 since there seems to be no evidence that under ordinary conditions oxidation 

 is ever likely to progress so far as to result in the use of baths injurious to 

 cattle, the question of the use of formaldehyde is purely economic. The writer 

 believes that in most cases it will be cheaper to let some of the arsenic go to 

 waste through oxidation. When the cost of a gallon of formaldehyde about 

 equals the cost of all the materials necessary to make 50O gal. of dipping bath, 

 there will probably be little financial gain either way, while there may be some 

 real profit in its use through saving of labor in preparing [the] dip and through 

 the reduction of offensive odor from the bath by keeping it under antiseptic 

 conditions." 



Contribution to the study of " marginal points " of the blood of mammals, 

 A. Laveran and G. Fbanchini {Bui. 8oc. Path. Exot., 7 {1914), No. 7, pp. 580- 

 584). — This is in large part a review of the subject with references to the 

 literature. 



The protection of parasites in the digestive tract against the action of the 

 digestive enzyms, W. E. and E. L. Busge {Jour. Parasitology, 1 {1915), No. 4^ 

 pp. 179-183, figs. 3). — "Tapeworms and roundworms from the intestine of the 

 dog are not digested when introduced into activated pancreatic juice so long 

 as they remain alive, but are digested when dead. If any part of them be 

 killed this part is digested. A dead roundworm which is ordinarily digested 

 when introduced into activated pancreatic juice can be prevented from being 

 digested by keeping the dead body wall constantly permeated with nascent 

 oxygen. The oxidative processes of the living parasites enable them to with- 

 stand the action of the digestive juices by oxidizing the enzym solution imme- 

 diately in contact with them." 



Experimental drug treatment of East Coast fever of cattle, G. H. F. 

 NUTTALL {Parasitology, 8 {1915), No. 1, pp. 56-87, fig. i).— The experiments here 

 reported have been summarized by the author as follows : 



" No drug has been found which will infiuence the fatal course of East 

 Coast fever or retard the multiplication of Theileria parva in the blood of the 

 affected cattle. The drugs which were tried with negative results were trypan- 

 blue, Congo red, tryposafrol, creosote and oleum copaivse, arsacetin, soamin, 

 606, emetin hydrochlorid, mercury salicylate, mercury succinimid, quinin bihy- 

 drochlorid and hydrochlorid, ethylhydrocuprein, ammonium fluorid, potassium 

 iodid, sodium salicylate, calcium lactate, and nuclein. 



